Sacrifice Mage

Summoned. Sacrificed. But sent back to life with a star for a mana core.

Ross Moreland dearly wishes to spice up his dull life as a PA with something actually exciting. Like magic. His wish comes true when he gets summoned to another world. Then he gets ritually sacrificed.

Luckily, the banished sun god rejects it, sending him back to life with a starlike core, one that gathers a ton of mana to explode into being. Ross can't use up the mana fast enough to prevent a fatal detonation with regular spells. What he can do is Sacrifice it all away, in return for incredible rewards. First, he just needs to join the very cult that tried to kill him.

Convincing them that a declining cult needs a cultist with a star core is the easy part. If Ross wants to get a handle on his mana core, he'll have to navigate through evil nobles, fanatical vampires, and a sunless city that despises the weak. Good thing that it's Ross's turn to play with Sacrifice.