Lovely battle.Calamity is a ruthless magic monster with the life leech ability,but the only thing i don't like about him,is its electried ability of -1 to all monnster both allies and enemies, though in this case your summoner granted it painforge.
Secondly, most times if I am using Dar tottem gearmut as tank,I pair a monster like meriput magician that has tank heal or a summoner with the heal ability as well.Arachne weaver tried to sustain your tank with corrupted healing but did not last long in the battle.Anyway kudos 👏 to you.