I had trouble against AI3 in the trainer. Most of it was just bad opening hands, though. I had large problems surviving the first few turns if my opening hand had less than 3 pillars. I'm also bad with timing when it comes to dropping the Chimera.
While messing around with the Nightfall idea for a short 10 games, I had some success with this:
52g 52g 52g 52g 52g 52g 52n 52n 52n 52n 52s 52s 5bs 5bs 5bs 5bs 5bs 5bs 5c3 5c3 5c3 5c5 5c6 5c6 5c6 5de 5de 5up 5up 5uq 5uq
?? = Life Pendulum
-1 Bone Pillar, -1 Aflatoxin, -1 Emerald Pillar, -2 Heal, -2 Chimera
+1 Thorn Carapace, +1 Empathic Bond, +2 Life Pendulum, +2 Nightfall, +2 Steal
This version is still unbalanced but it had an easier time with it (read: idiot friendly version).
As for other ideas:

Take Gravity Pull with Chimera; Otyugh

Nightmare (on Cells and Skellies)