Cataclysm

When you cast this spell you can choose to have some of your HP siphoned, select targeted area within 300 ft , you still to drop a gargantuan meteor made of necrotic malice,
on the following turn the target must make a dex save on a failed save the malice impacts dealing 12d6 necrotic and 12d6 force, along with additional force damage the caster drew from it
own personal hit points, on a success the target takes half damage,
the next following turn of the caster the ground zero of the initial impact explodes again with necrotic energy where X of the
health the caster that poured into the spell upon casting.

AT HIGHER LEVEL; the damage of the initial impact deals and extra 4d6 Necrotic and Cold damage per level above 7th.