Heroes:

Bluebird

The New 52 introduced Batman sidekick.  Based on the Hotshot deck from Transformers Armada: Battle For Cybertron and uses a card by Tokyotalks2much.  

Katana

The epic swordswoman with a sword that stores the souls of the people it kills.  Loosely based on a design by Rich Pizor.

Villains:

Punchline

The new Harley Quinn introduced in 2020's Joker War.  Uses cards by Roman Farraday and BML Designs. 

Sportsmaster

The long time D-list villain introduced in the 40's and turned into a C-list villain by the "Young Justice" TV show.  Uses cards created by Roman Farraday, Robert Moore, and  P. D. Magnus.