Dark Souls Remastered | Defeating the Berenike Knight in Undead Burg and getting a Fire Keeper Soul

This is on NG+1 (NG+). Some might say he is a miniboss. Once he's defeated, he never respawns the same playthrough. He doesn't drop anything great, but it's the item behind him (a Fire Keeper Soul) that is very useful.

A Fire Keeper Soul can be used to reinforce your Estus Flask, which is a permanent effect (even into future playthroughs). You can also consume a Fire Keeper Soul and it will grant 5x Humanity and restore full health (consumption is not recommended until your Estus Flask has already been fully upgraded).

He dropped:

4000 souls
Greataxe
Titanite Shard