This is basically imexile's Detonate Dead of Chain Reaction core with an Original Sin slapped onto it and a few other league relevant changes.

Single target can be pushed higher by switching in Unbound Ailments or going Temp Chains over punishment.

Swap Faster Casting for Arcanist Brand on hard bosses.

see also: Ventura's corpse pool guide

PoB (high investment, not min-maxed): https://pobb.in/RW26k-0qM-L4