"Escape to Salvation" - "Magnificent Retreat" [Campaign 4, Mission 4]

Completed the scenario on the Hero difficulty. I still couldn't catch Centerperk. Used Darkness and Summoning spells. The difficulty was only noticeable once when a dwarf stormed the castle (I had to replay it three times). The gates weren't breaking (even with a catapult). But teleporting them one by one... that's a sure death... they attacked as a group. The rest were defeated on the first try. The battle with Biara: I had two main units (a subordinate and a phantom) and a spell in my pocket. Biara, when she has two stacks left, starts spamming weak meteor showers (trying to get rid of my phantoms and forgetting about summoning my units). I managed to cast two other spells twice (Dispel and Slow, but they didn't help much). Her own archdevils helped more. The archangels quickly died after jumping over the wall. Only the stupid cyclops and lava dragons remained. The right build is the key to victory!