Vez'nan

From his tower he casts a hold on your towers during waves 9-15 (wave 9: 2 towers every 13 s; wave 10: 3 towers every 13 s; wave 11: 4 towers every 14 s; wave 12: 5 towers every 14 s; wave 13: 6 towers every 16 s; wave 14: 7 towers every 16 s; wave 15: 8 towers every 18 s). A held tower stops at once; click it 3 times within 4 seconds to free it, otherwise it stays held for 6 seconds more (10 seconds in all).

During waves 6-15 he opens demon portals. Wave 6: portal 1 every 15 s, up to 3 times. Wave 7: portal 1 every 10 s, up to 2 times. Wave 8: portal 2 every 20 s, up to 3 times. Wave 9: portal 1 every 15 s, up to 3 times. Wave 10: portals 1 and 2 every 20 s, up to 3 times. Wave 11: portals 1 and 2 every 15 s, up to 3 times. Wave 12: portals 1 and 2 every 15 s, up to 3 times. Wave 13: portal 3 every 15 s, up to 3 times. Wave 14: portals 1, 2 and 3 every 15 s, up to 3 times. Wave 15: portals 1, 2 and 3 every 15 s, up to 3 times. Each portal sends a random group. Portal 1: 4-7 Demon Spawn (50%), 3 Demon Hound (30%), 5 Demon Spawn + 1 Demon Lord (20%). Portal 2: 2-5 Demon Spawn (50%), 2 Demon Hound (30%), 3 Demon Spawn (20%). Portal 3: 3 Demon Spawn. When he fights, portals 1, 2 and 3 open every 10 seconds, up to 40 times.

After the last wave he walks down to fight. When a hit would kill him, he turns into a demon with full health again: speed 18, and 8 hits of 666-999 physical damage to up to 8 units around him every 2.5 seconds.

When the demon falls, every other enemy on the battlefield dies.