Heeeeere’s Obsidius! Pretty interesting, the trait is amazing, the mana generation is confusing to evaluate (it’s probably on par with Infernus, but you can target it, and it’s destruction instead of explosion…)
The damage takes some explaining. I did some data mining; light splash damage refers to splash damage that deals 25% to adjacent troops (such as Goblin Rocket), and heavy splash damage (new to Gems of War) deals 75% to adjacent troops. So the damage is in one heavier hit and one conditional lighter hit, rather than two medium size hits.
Time for math! Assuming you have all the Magic kingdom bonuses, Infernus deals
(13 +12) = 25 base Magic
Splash: (25+10) = 35 base + 18 or 36 to adjacent
Expected Damage: Splash + Splash = 70 to one target, 106-142 total
(13 + 9) = 22 base Magic
Heavy Splash: (22+4) = 26 base + 20 or 40 adjacent
Light Splash: (22+4) = 26 base + 7 or 14 adjacent
Heavy Only = 26 to one target, 46-66 total
Heavy + Light = 52 to one target, 79-106 total
Expected Damage: Heavy + 0.25 x Light = 33 to one target, 55-76 total
On average, Obsidius deals about half the damage Infernus does, mainly because Obsidius has a much lower damage bonus inherant in its spell and because its second hit only happens 25% of the time. That last clause really confuses me as to why it’s there, because he deals less than Infernus even if the Light hit were guaranteed.
We’ll have to see if the trait and the mana generation make Obsidius better than Infernus in the long run. Infernus’ Divine typing would be an advantage but the Maraj Queen releases before Obsidius and that gives a source of starting mana.
EDIT: I also checked Vash’Dagon, and he can’t devour himself.