My personal favorites
Green Arrow: Arrows that can be shot in any direction and plus on block. They can also be used to mix up and make the opponent fuzzy guard, since his jump D+F arrow hits overhead(this is awesome with the freeze arrow). Not to mention he has arrows for zoning, pressure, and just about any situation. This character in general is highly dangerous.
Aquaman: A trait that craps on your strings and gives him a free block, enough said.
Batman: Bats that can be used to zone, rush in and start pressure, extend combos, anti air, keep you out, and just about anything. When the bats are out, you immediately think "Crap!"
Grundy: An unclashable command throw that can be meter burned to make it invincible and causes some decent damage when chained. This command throw can't be ducked either and has insane priority and pretty fast startup.
Bane: This characters trait is insane when used properly. When he knocks you down the wakeup nightmare games begin, and when you see that venom pumping, you start panicking. He can crap on your wakeip attacks and get you into a brutal guessing game. Command grab? F2-D BF2 F2 cancel? Also, his level three makes him immune to PROJECTILES!
Nightwing: A staff that has huge reach from mid range and a ground tracking projectile. This trait can actually change a matchup IMO. You can keep some characters at bay that lack good advancing normals and footsies. His 1f1 is godlike and plus on block, can also be hitconfirmed into a nasty combo. Has an overhead, and an untechable D3. In the corner this staff is brutal. And the ping ping sound is so awesome.
Doomsday: Doomsday gives no f#%$!s, he's getting in and theres nothing you can do about it.
Lex Luthor: If you let him activate that trait, the setups and screen control begin. Good luck getting passed mid screen.
