How it works?

[LordPidgeon]

Hello!
I`m playing a K'rrik, Son of Yawgmoth deck and here is my question. I`m at 2 lifes, I`ve already casted 4 spells and then I cast Aetherflux reservoir. It resolves and I want to cast a Viscera Seer paying 2 life. Would I lose? Would I be at 0 lifes and then gain 6 lifes?

Thanks for the answers.

[ApothecaryGeist]

You will cast the Viscera Seer spell and pay it's costs, choosing to pay 2 life for the black mana.  The spell will go onto the stack and you will be at zero life.  Aetherflux Reservoir will trigger.  The ability will go on the stack.  At this point, state-based actions will check.  You are at zero life (with Viscera Seer on the stack and an Aetherflux Reservoir trigger on top).   You will die.  Before the Aetherflux Reservoir trigger can resolve. 

[LordPidgeon]

Thanks for the quick answer!