Roster Help Please

Marvel Puzzle Quest MPQ Tips and Guides Roster and Level Help
1

I’ve been away from the game for about a year.

My current roster looks like this, and I’m not sure what exactly championing is.

What should I be doing? Should I sell some of them off for space? According to my SHIELD resupply I’m on day 175 if that’s relevant information.

Thank you for any help and time you give.

2

I’ve just championed Storm and OBW for now.

I’m going through the lightning rounds, but all I get from the drops are the 1* characters.

Do you think it would be worth it to try to place in the PvP/PvE events, or should I just gun for the ones that drop covers for the characters I already have?