Set Avani as your Arena lead and have Rahgan as sub instead. Avani is amazing in Arena.
You can get done characters in Raid but they're not that good. Raid is for farming rare materials to craft incredibly powerful spheres like Malice Jewel (30% all stats), Buffer Jewel (35% all stats) and Occult Treasure (40% all Stats)
Does it matter that Avani is 5* and Rahgan is 6* or should I swap it after Avani is 6*?
I need to do raids more then.
^^
Edit:
I evolved Avani to 6* and tried it as leader.
-> Cant get skills ready to 2nd turn.
->> 6* Rahgan back to leader, his leader skill helps building BB with normal hits.