if you have a bunch of low cost cards you use Immoliation to put a few ash eaters or something in play
Actually, the most common uses of immolation are with Photons/Gnome riders + Lava golems. Ash eaters use to be too expensive to immolate and too weak for main attackers.
They just sit around, eat ash, and generate quanta.
EDIT: They generate quanta, right?