I did a replay and I found what I missed in the end.
However, what to do with the [Heart of the Warmonger]? It didn't seem to have triggered anything by wearing it.
Ah, so I couldn't fit it into the description, but you need a Health stat above the threshold to actually trigger its effect.
It gives an insane regeneration buff each turn that you don't take damage.
Ah ok, I thought it triggered some secret ending because they didn't want to tell me what it does x)
But I really like the rest. Looking forward to the other additions.