They probably don't go in the same deck, unless you're playing a Naya Superfriends build, like a Sisay Weatherlight Captain or Jodah the Unifier, both of which would proabably love Serah, and have big splashy direct-damage haymakers for Lightning to boost after she connects
As a kid I just liked the big monsters and didnt really understand the rules
The rewards vary, but usually, they unlock exclusive cards and cosmetics
Booster Fun Variants Magic: The Gathering | Avatar: The Last Airbender Booster Fun variants include Borderless Field Notes versions of various creatures from the world, Borderless Elemental Frames, Full-Art Borderless DFCs, and Extended Art cards
We lived miles away from one another, so instead of meeting up, we'd call each other, play a game, and try to remember what the board states were