I remember the cost of converting Orc Castles; I won't pay it. :)
The Orcs don't arrive at the Castle in full force; before that, they are weakened by magic and arrows, sometimes even by their own Cyclops. :)
But for now, I've built up a decent defense, with creatures from levels 1 to 5, I'm at level 24, I have a portal to the city (and that's very important; I'm almost at the required level of 25, with only 10k experience left), I have some good artifacts, I traded for Cyclops at the artifact merchant for Mentor and acquired the Phantom Staff – it won't be superfluous, and I hope that the Succubi in that quantity will be able to destroy the catapult (or force the Orcs to destroy it), because in battles outside the Castle, I lose only up to 14 units of troops. And, which is not so bad, with the Guild, there is still a general Scatter effect on Expert difficulty :) (but no Slow). But I only have 6 Spell Points (at the same level 24) – 2 of my own, 2 from the staff, and 2 from the armor.