yeah that's what i'm thinking also their skills able to cover lot of areas
Amaterasu - aoe blind, team def up + regen and atk + def down(B frame)
Dark Amon - prolong stun duration, def down(A frame) and high dmg when boss in rage + rage bar down(massive! usually cut like 30%)
and
what u missing here probably status immunity/cleanse, atk down(A & C frame), def down(C frame), heals and etc....but as a fresh start, it is great