Just some ideas that have been in my head randomly...

Keyword

Cover – Exhaust this charecter. It may replace an adjacent charecter as defender for this attack. If you do, your opponent may deal breakthrough damage this attack as though there was no defender.

Loyalty-All Recruit this charecter only if you control charecters that have all this card's affiliations.

Superman, Public Enemy
Rarity: U
5 drop
F/R
Team Superman/Gotham Knights
Cover
Loyalty - All
Cosmic: Superman gets +3/+3.
9/9
“You always think we can take them.”

Superman, Angel of Metropolis
Rarity: Common
6 drop
F/R
Team Superman
Cover
Substitute
Cosmic – Whenever Superman becomes a defender during combat, he gets +2 ATK/+2 DEF this turn.
"What's so wrong about truth, justice and the American way?"
12/11

Superman, Man of Tomorrow
Rarity: R
7 drop
F/R
Team Superman/JLA
Cosmic, Cover
Remove a cosmic counter from Superman> Choose one: Ready Superman, stun target character with cost five or less, Superman gains invulnerability this turn, or target character cannot ready this turn.
“Only the weak succumb to brutality.”
17/16

Call on Me
Rarity: C
Cost: 2
As an additional cost to play Call on Me, exhaust a character you control.
Search your deck for a character with cost 4 or greater that shares an affiliation with the exhausted character, and reveal it to all players. Put that card into your hand and shuffle your deck.

Green Lantern's Light!
Rarity: R
Cost: 2
Play only during the recovery phase.
If the total willpower among all characters you control is greater then 25, put the top card of your deck into your resource row.

Will add more from my list later... what do you guys think?

For cover, does it mean that it would still cause breakthrough regardless of reinforcement?

one more thing on cover. when you say "our opponent may deal breakthrough damage this attack as though there was no defender." does that mean even if i have my big 7D cover im still gonna take Breakthrough as if he had no DEF? if so whats the point of cover?

Man of Tomorrow and Public Enemy look a bit too powerful. Maybe you should reduce Man of Tomorrow's cosmic to only +2/+2 or give him some heavy loyalty(Like discarding a Team Superman character or controling a Team Superman character with a cost of 3 or less). Man of Tomorrow should say only once per turn. I mean, attack, remove counter > ready, attack + Sun Powered, remove counter > ready, attack again. That is like 53 damage with only two cards.


Here are some ideas:

Gypsy, Bird of Prey
Cost: 1
Gotham Knights, JLA
ATK: 2, DEF: 1
Reservist, Concealed - Optional, Evasion
Pay 2 endurance, move Gypsy from your hidden to your visible area >>> Look at the top card of your deck. You may put that card in your KO'd pile.
Activate >>> Move Gypsy and target non-stunned character adjacent to Gypsy to your hidden or visible area. Use this power only during the recovery face.

Zinda Blake <> Lady Blackhawk, Bird of Prey
Cost: 2
Gotham Knights, Blackhawks
ATK: 3, DEF: 3, Range
Reservist
As an additional cost to recruit Zinda Blake reveal a Gotham Knights or Blackhawks character card from your resource row.
Zinda Blake gets +1 ATK and +1 DEF if equipped.
Characters with flight you control have +1 DEF.
Boost 1: When Zinda Blake comes into play, search your deck for an equipment card with cost 0 and equip it to Zinda Blake. Shuffle your deck. Characters you control have flight this turn.