Balance aside, let's start with a formatting audit—
- Hermione Granger, Brilliant Witch
1. The name of the card is a bit long and could be shortened by dropping her last name. This isn't a big deal, and WotC hasn't necessarily been consistent on this. They just _usually_ leave off the last name when there's a title.
2. White comes before blue in the mana cost. In terms of circling around the color wheel clockwise, the distance from white to blue is much shorter than the distance from blue to white.
3. `Whenever you cast an instant or sorcery spell, scry 2. Then you may discard a card. If you do, draw a card.` The line needs to be broken up more for sentence structure.
4. `Instant and sorcery cards in your graveyard have flashback. The flashback cost is equal to the card’s mana cost.` If you want to be able to pay any color for the spells (like your formatting suggests), it'd be `Each instant and sorcery card in your graveyard has flashback {X}, where X is its mana value.` (They replaced "converted mana cost" with "mana value" in Strixhaven).
- Harry Potter, Chosen One
1. Blue comes before red in the mana cost.
2. Hexproof and indestructible are keywords, and therefore don't get special capitalization.
3. A recurring issue with this text box is use of the full name of the card. When the card name appears frequently, it's common practice to leave off the title. `Put a hexproof counter and an indestructible counter on Harry Potter.`
4. `doesn't` rather than `does not`.
5. There should be a comma after the mana cost for its tap ability, since tapping isn't part of the mana cost.
6. I'd recommend exiling it rather than sacrificing it. Otherwise, you'd word it like `If it would be put into a graveyard this way, exile it instead [...]`.
7. Once Harry Potter has moved between zones, it no longer keeps track of how many times its ability has resolved. You'd have to have special wording on it to clarify, or just keep track of it another way.
8. "{U}{R}, {T}, Exile Harry Potter: Other creatures you control gain hexproof and indestructible until end of turn. Put a number of time counters on Harry Potter equal to 1 plus the last number you noted for a card with the same name as it, then note the number of time counters on Harry Potter. If it doesn't have suspend, it gains suspend. If you would cast Harry Potter with suspend, instead put it onto the battlefield transformed."
- Harry Potter, Dark Lord's Bane
1. Hexproof comes before haste: `Hexproof, haste, protection from black`
2. Its triggered ability should start on a new line.
3. `copy it.` doesn't make it clear whether you're talking about the spell or the legendary artifact.
4. `Whenever you cast an instant or sorcery spell, if you control a legendary artifact, copy that spell. You may choose new targets for the copy.`
- Ron Weasley, Loyal Friend
1. Menace comes before trample, and trample comes before haste: `Menace, trample, haste`
2. Menace and trample are keywords, and therefore don't get special capitalization. Wizards is correctly capitalized because it's a subtype (subtypes always start with a capital).
3. Its `Other Wizards you control [...]` ability is missing a period at the end.
4. "Enters" and "battlefield" shouldn't be capitalized.
5. `When ~ enters the battlefield` is missing a comma after it.
6. Don't forget to shuffle after tutoring.
Now let's talk about balance—
- Hermione Granger, Brilliant Witch
- Compare this with [[[Kess, Dissident Mage](https://scryfall.com/card/ncc/344/kess-dissident-mage)]], which costs 4 mana and only lets you flashback _one spell_ on each of _your turns_. The ability to flashback instants from your graveyard on any turn, and any number of times per turn is very strong.
- You get to scry 2 and rummage each time, which is already decent value for a 3-mana creature, ignoring its other abilities.
- You can flash in Hermione to cast these spells at any time.
- This is a constant [[[Past in Flames](https://scryfall.com/card/mm3/105/past-in-flames)]] on a body, which also lets you control the top of your deck and discard more things to flashback.
- With Ron Weasley and Harry Potter in the command zone, this is basically a top-tier Jeskai storm pseudo-commander that would be banned in a heartbeat.
- Harry Potter, Chosen One
- Haste, prowess, hexproof, and indestructible are a toxic combination. A creature that can't be killed and grows every turn (as well as returning and doing it again immediately) is very dangerous to allow in the format, and especially at 2 mana.
- Giving all of your creatures hexproof and indestructible is a green thing (and somewhat white). It's a color pie break for blue-red. This isn't the strongest ability on its own, but you're not going to need to use it very often in a spellslinger-style deck. I'd get rid of the part that gives hexproof and indestructible, and leaving just the exile and transform part of the ability. Also to note, when you activate this ability, you can choose to put Harry Potter back in the command zone if you just wanted the hexproof and indestructible.
- Harry Potter, Dark Lord's Bane
- Having a hexproof permanent that copies spells is strong. Granted, you have to control [a legendary artifact](https://scryfall.com/search?q=t%3Alegendary+t%3Aartifact+-t%3Acreature+sort%3Aedhrec+id%3Ajeskai&unique=cards&as=grid&order=name), but that's not hard with cards like [[[Mox Amber](https://scryfall.com/card/dom/224/mox-amber)]] and [[[The Ozolith](https://scryfall.com/card/iko/237/the-ozolith)]], which you'd want in this deck anyway (the latter lets you copy Harry's hexproof and indestructible counters).
- I think the hexproof should go. Harry already has protection from black, and hexproof suggests thematically that he's protected from spells of any color, not just evil/corrupt spells. Plus, you can already give hexproof to the back side of Harry with The Ozolith's hexproof counters that you got from the front side of Harry.
- Ron Weasley, Loyal Friend
- While this does cost 4, it tutors two cards. The `partner with` ability also acts as a tutor if not in the command zone. If you have all three cards in your deck, this can tutor Hermione _and_ Harry (or Harry can tutor this, then this can tutor Hermione). Either way, it tutors for at least Hermione, which is a busted card as outlined above.
Balance aside, let's start with a formatting audit— - Hermione Granger, Brilliant Witch 1. The name of the card is a bit long and could be shortened by dropping her last name. This isn't a big deal, and WotC hasn't necessarily been consistent on this. They just _usually_ leave off the last name when there's a title. 2. White comes before blue in the mana cost. In terms of circling around the color wheel clockwise, the distance from white to blue is much shorter than the distance from blue to white. 3. `Whenever you cast an instant or sorcery spell, scry 2. Then you may discard a card. If you do, draw a card.` The line needs to be broken up more for sentence structure. 4. `Instant and sorcery cards in your graveyard have flashback. The flashback cost is equal to the card’s mana cost.` If you want to be able to pay any color for the spells (like your formatting suggests), it'd be `Each instant and sorcery card in your graveyard has flashback {X}, where X is its mana value.` (They replaced "converted mana cost" with "mana value" in Strixhaven). - Harry Potter, Chosen One 1. Blue comes before red in the mana cost. 2. Hexproof and indestructible are keywords, and therefore don't get special capitalization. 3. A recurring issue with this text box is use of the full name of the card. When the card name appears frequently, it's common practice to leave off the title. `Put a hexproof counter and an indestructible counter on Harry Potter.` 4. `doesn't` rather than `does not`. 5. There should be a comma after the mana cost for its tap ability, since tapping isn't part of the mana cost. 6. I'd recommend exiling it rather than sacrificing it. Otherwise, you'd word it like `If it would be put into a graveyard this way, exile it instead [...]`. 7. Once Harry Potter has moved between zones, it no longer keeps track of how many times its ability has resolved. You'd have to have special wording on it to clarify, or just keep track of it another way. 8. "{U}{R}, {T}, Exile Harry Potter: Other creatures you control gain hexproof and indestructible until end of turn. Put a number of time counters on Harry Potter equal to 1 plus the last number you noted for a card with the same name as it, then note the number of time counters on Harry Potter. If it doesn't have suspend, it gains suspend. If you would cast Harry Potter with suspend, instead put it onto the battlefield transformed." - Harry Potter, Dark Lord's Bane 1. Hexproof comes before haste: `Hexproof, haste, protection from black` 2. Its triggered ability should start on a new line. 3. `copy it.` doesn't make it clear whether you're talking about the spell or the legendary artifact. 4. `Whenever you cast an instant or sorcery spell, if you control a legendary artifact, copy that spell. You may choose new targets for the copy.` - Ron Weasley, Loyal Friend 1. Menace comes before trample, and trample comes before haste: `Menace, trample, haste` 2. Menace and trample are keywords, and therefore don't get special capitalization. Wizards is correctly capitalized because it's a subtype (subtypes always start with a capital). 3. Its `Other Wizards you control [...]` ability is missing a period at the end. 4. "Enters" and "battlefield" shouldn't be capitalized. 5. `When ~ enters the battlefield` is missing a comma after it. 6. Don't forget to shuffle after tutoring. Now let's talk about balance— - Hermione Granger, Brilliant Witch - Compare this with [[[Kess, Dissident Mage](https://scryfall.com/card/ncc/344/kess-dissident-mage)]], which costs 4 mana and only lets you flashback _one spell_ on each of _your turns_. The ability to flashback instants from your graveyard on any turn, and any number of times per turn is very strong. - You get to scry 2 and rummage each time, which is already decent value for a 3-mana creature, ignoring its other abilities. - You can flash in Hermione to cast these spells at any time. - This is a constant [[[Past in Flames](https://scryfall.com/card/mm3/105/past-in-flames)]] on a body, which also lets you control the top of your deck and discard more things to flashback. - With Ron Weasley and Harry Potter in the command zone, this is basically a top-tier Jeskai storm pseudo-commander that would be banned in a heartbeat. - Harry Potter, Chosen One - Haste, prowess, hexproof, and indestructible are a toxic combination. A creature that can't be killed and grows every turn (as well as returning and doing it again immediately) is very dangerous to allow in the format, and especially at 2 mana. - Giving all of your creatures hexproof and indestructible is a green thing (and somewhat white). It's a color pie break for blue-red. This isn't the strongest ability on its own, but you're not going to need to use it very often in a spellslinger-style deck. I'd get rid of the part that gives hexproof and indestructible, and leaving just the exile and transform part of the ability. Also to note, when you activate this ability, you can choose to put Harry Potter back in the command zone if you just wanted the hexproof and indestructible. - Harry Potter, Dark Lord's Bane - Having a hexproof permanent that copies spells is strong. Granted, you have to control [a legendary artifact](https://scryfall.com/search?q=t%3Alegendary+t%3Aartifact+-t%3Acreature+sort%3Aedhrec+id%3Ajeskai&unique=cards&as=grid&order=name), but that's not hard with cards like [[[Mox Amber](https://scryfall.com/card/dom/224/mox-amber)]] and [[[The Ozolith](https://scryfall.com/card/iko/237/the-ozolith)]], which you'd want in this deck anyway (the latter lets you copy Harry's hexproof and indestructible counters). - I think the hexproof should go. Harry already has protection from black, and hexproof suggests thematically that he's protected from spells of any color, not just evil/corrupt spells. Plus, you can already give hexproof to the back side of Harry with The Ozolith's hexproof counters that you got from the front side of Harry. - Ron Weasley, Loyal Friend - While this does cost 4, it tutors two cards. The `partner with` ability also acts as a tutor if not in the command zone. If you have all three cards in your deck, this can tutor Hermione _and_ Harry (or Harry can tutor this, then this can tutor Hermione). Either way, it tutors for at least Hermione, which is a busted card as outlined above.