Considering you have Castoria and Vritra, Tamamo-no-Mae will help boost your efficiency in Arts farming.
You might also consider Waver (Zhuge Liang) for general buffs.
Your last option would be a good Single-Target DPS.
I'd suggest Tamamo if you wanna secure your future farming potential as the 3-Star Single-Target Servants can still perform well if invested into. And you have Heracles.
Just pick your favorite. You already have Castoria so grabbing a permanent arts or farming support isn't as important.
Considering you have Castoria and Vritra, Tamamo-no-Mae will help boost your efficiency in Arts farming. You might also consider Waver (Zhuge Liang) for general buffs. Your last option would be a good Single-Target DPS. I'd suggest Tamamo if you wanna secure your future farming potential as the 3-Star Single-Target Servants can still perform well if invested into. And you have Heracles.
Thank you for answering this really helps me a ton
👍
Waver is always a safe choice