[HoMM5 Tournament OFF] The fifth stage of the John Van Caningham Memorial Tournament.

Understood.
I confirm that in the submitted walkthrough for the contest, on day 13, I headed towards the Knights of Isabel, visited the Sphinx (level 17).
On day 14, I acquired a Rakshasa, went to the tree (level 18 - Enchanted Charm), and defeated the Necromancer in auto-battle.