Just revealed the super-disappointing bug that turned flawless victory into total defeat...
The Succubus L3 tried to charm the fat bastard as the second closest enemy to her. She failed and the king didn't turn around, but he became the ally for spells (just not clickable as the bard, for instance). So, I was unable to apply two Curses L3 subsequently to do 18 damage in 6 turns and lost everything