I agree with @Dawnsky, you’re doing great.
If team 1 is your defence team, you need to move Belith out of tank. Swap her with Gormek or Gunnar.
Or, an alternative lineup to try is: Belith / Gunnar / Gormek / Bane / Balthie. The reason is tile matching. Your opponent will send down purple to get Bane, the ones that hit Balthie will charge him up. Same for the blue tiles sent to hit Gormek, they will charge Gunnar. Play around with this order, but in a rainbow team, you should try to group Yellow & Purple and Blue, Green & Red.
In terms of deciding your ascension priority. Valen is an excellent blue hero, and is worth levelling before Greymane and Ulmer. You won’t need more than one Oberon in the long run, so don’t worry about levelling that third one at all.
The only 2* worth levelling is Sha Ji. Healers are valuable at every stage of the game, and it may be a while before you get a suite of 3* or 4* healers. Leave Farid at his current level, and level a second Azar (unless you get another red hero or the items to ascend Gormie)
Great work levelling a second Bane - you will use both in events for a long time to come.
Keep reading the forum, especially the player guides. In case you haven’t already read it: