Boss: Flame Leviathan (heroic mode)+4 towers
Guild: Забытое братство (Forgotten brotherhood)
Server: Ясеневый лес (RU)
PoV: Salvaged Siege Engine

My guild has not attempted to do before this hardmode, boss is not difficult, and died with the fourth attempt. Only what we needed - it is to stay alive :)
This video not tutorial i made it for fun and my guildmates.