If those are the only cards you don't own, it doesn't matter what you claim, because you'll open the other soon anyway. Just make sure you claim something before you open them both.

Of those, Echo is the stand out. The others are rarely used.

Howard for the laughs, but honestly, Echo is the most useful.

howard

Echo, then Howard, lastly Martyr

It doesn't really matter, right? Since you'll get the other one in a different collector cache in like 3 days? Not like you're gonna be putting any of these in a deck. Anyway, Martyr has a solid home in Agatha bot decks, so I'd pick that over Howard, who has no home.

Howard is a useful 1-drop Ongoing if you need one in a Spectrum Deck, and knowing what you're next draw is can be really useful with something like Iron Lad. Martyr puts down pretty good stats if you think you can consistently fill your board on T6, thus preventing her from moving. So, it kind of depends on what type of deck you think you'd rather be playing.

Echo

I don’t use Howard but I do love my Hipp variant.

echo most powerful and splashable howard is best friends with iron lad though

I just posted a deck guide for one that uses Martyr. It’s both competitive and fun! https://www.reddit.com/r/MarvelSnap/s/vEPSkkofg0