Look at the following cards:
Doppelganger, Killer Clone
Character, Underworld, Cost: 1
3 ATK/0 DEF
You may pay 5 endurance rather than pay Doppelganger's recruit cost while you control a Sinister Syndicate character.
MTU-135 - Common
Is it legal in a BYOT Underworld deck?
And in a BYOT Sinister Syndicate deck?
Different card, similar questions:
X-23, Laura Kinney
Character, Unaffiliated, Cost: 3
8 ATK/4 DEF
Mutant - Physical
To recruit, discard two cards.
X-23 gains the X-Men affiliation while you control another X-Men character.
MXM-190 - Rare
OK, it is legal in an X-Men deck.
Would it be legal in a (insert a different affiliation) deck?
Thank you in advance