I managed to get him on Android, I didn't check if his art was there or not. I also have the placeholder Euryali.
First impressions are... Underwhelming. Damage isn't particularly high and unlike ketras, Gard and Pharos there is no easy way to boost it. Exploding 5 gems isn't enough to do anything other than give a couple of troops a little bit of mana. So he falls into that no man's land of being not very good at damage and not very good at gem filling.
His mythic trait doesn't feel very mythic given that burn isn't of that much use, and the only troops that scale off it don't work well with him. Perhaps I'd feel differently about his trait if I had Elemaugrim.
Ultimately I would rather take The Dragon Soul out than Infernus. At least when I cast TDS he fills a couple of troops (or at least puts them 1 match away from being filled).
TDS: 16 cost, explodes most of the board, deals up to 80 damage.
Infernus: 22 cost, explodes a quarter of the board, deals 90 damage.
Perhaps infernus should either scale off burn, or do his damage to one troop (although that would make him too similar to ketras I guess).
So far I've been having a bit of fun pairing him with gorgotha and forest guardian, and also in a different with Sheggra. Maybe there's a killer team I'm missing. Hmm back to the team building menu for me!