The Nemesis: the monster that killed you remembers

In The Ember Depths the monster that kills you can become your nemesis: a name, an epithet, a rank and a grudge. It comes back stronger until you take revenge.

Die to an elite, a champion or a wanderer (and sometimes a plain grunt) and it gets a name, an epithet and a crown. It gloats on your death screen. Then it goes looking for you.

Up to 3 nemeses at a time. Each kill of you promotes it (rank 5 at most): more levels, more elite affixes, more health and damage.
It turns up again in its own dungeon, elsewhere in its act, or near its depth in the Descent, more likely the longer it's been (45% a floor at most), never right on the stairs.
Vengeance: kill it for 3× XP, a guaranteed epic, a chance at a legendary that grows with its rank, and a shower of gold. Its trophy goes in your Hall of Vengeance.
In co-op, a friend's nemesis can walk your floors too. Help them settle it.

Rank	Level	HP	Damage
1	+1	+15%	+8%
2	+2	+30%	+16%
3	+3	+45%	+24%
4	+4	+60%	+32%
5	+5	+75%	+40%