What happens when I redirect multiple large sources of damage through the en-Kor ability to Mogg Maniac?
Mogg will deal 18 damage, but it will deal it after dying.



The en-Kor's redirection only works if you activate it before they take damage. When you activate their redirection ability, it creates a shield that will redirect the next point of damage it would take.

The redirection shield is a replacement effect. It causes Inferno to deal damage to Mogg instead of the en-Kor. Inferno still deals all of its damage simultaneously.

This is how the game progresses:


You cast Inferno (and retain priority).
Six times,

You activate Shaman en-Kor's first ability targeting Mogg.
Shaman en-Kor's first ability resolves, creating a shield that will redirect damage later.

Six times,

You activate Nomads en-Kor's ability targeting Mogg.
Nomads en-Kor's ability resolves, creating a shield that will redirect damage later.

Inferno resolves.

It will simultaneously deal 18 damage to Mogg and 6 damage to each player. Simultaneously, life is subtracted from players' totals, damage is marked on Mogg and Mogg's ability triggers.

State-based actions are performed simultaneously.

Any player with non-positive life lose the game. (I'm going to assume noone loses here.)
Mogg is destroyed for having marked damage exceeding its toughness.

Mogg is put in the graveyard from the battlefield.


Mogg's triggered ability is placed on the stack targeting your opponent.
Mogg's triggered ability resolves.

It deals 18 damage to the targeted opponent.



Note that Mogg only takes damage once in this scenario (even though some of it was originally intended for the en-Kor), so its ability only triggers once for the entire 18 damage.