Keeper of Souls is an A rank. At the end of the day, its a 1 color converter and is heavily reliant on your 1st troop not being impaired.
… I’m trying my best not to move your entire Tier list again, I don’t care enough. Its tough though.
Krystenax is a B rank. Denial of colors is a great effect when used properly, but I’d rather use Astral Spirit for empowered or 2 color converter if I’m targeting specific denial. Or I could just win from filling 15 mana. Its one of those games now.
Sheggra/The Great Maw combo is non-existent on the current version of the game, so I’d gladly suggest decoupling them. Both are C rank individually (I can’t believe I’m defending Sheggra. I think it could use a minor buff like create more red gems based on burning enemies), but Sheggra gains more potential over time while The Great Maw is losing potential over time (Bless/Impervious). Enjoy it in Switch land, though its probably irrelevant there too at this point.
Carnex is a C rank and don’t expect me to think positive of it in its current state. 25% skull reduction is not good enough for 1st slot usage and 15 mana to explode a fixed 10 skulls is bad value, especially when there’s less than 10 skulls on the table. It has bells and whistles, but fails at its primary function.
King Mikhail/Urskula are both C ranks separately. Urskula may eventually be useful (not holding my breath). King Mikhail is overcosted, but decent. KM could use some kind of buff (either traits or mana cost). Urskula exists to eventually make something useful, one day.
(Scatter damage typically sucks unless it has some kind of giant boost ratio that gives it equivalent to AoE damage)