Hi. What characters, if anyone, have the ability to feed yellow AP?
Loki and Hood aside. While they can feed yellow it’s not that they’re specialized in.
Besides 3* Thor’s red ability adding just a few yellow to the board, there isn’t any others in this tier.
In the 4* tier, you have Kinpin’s purple ability. Now lately, I like Cloak & Dagger once you play pocket dimension, Dagger adds 2 yellow to the board (or 3 at higher levels) at the beginning of every round. It add’s up quickly and some match for you automatically.