I just overpowered them for my fights, but if I wasn't looking to do that, I'd probably go with OBW to extend the countdowns and someone who can steal those tiles they put out (She-Hulk, Moonstone, Ant-Man, etc)..
That is great advice, thanks. I keep on forgetting to use some of the characters if they don't show up on the first roster page when choosing your heroes, even if they aren't powered up for the event some of my championed characters are still viable.
Speaking of champions I got a bit of a conundrum. I have a couple characters (Captain Marvel 3 star and Cyke 3 star to be exact) that are about to be maxed and able to be promoted but I have a couple covers sitting in my pile for them that are for colors that are maxed for them but would be very useful as soon as I promote them. I'm afraid they are going to expire before I get another cover for them though. Do I just sell them right before they expire and accept the loss or do I spend CP points to promote their powers?