Took this guy down last night. First attempt lead to a wipe, due to adds.... adds spawn based on time not % of hpts, so best to burn mob down quick. Second attempt was a breeze.
Mob was partially slowable with Balance of Discord. As adds began to pop, the druid grp healed and off tanked the adds. Cleric CH'd the tank and we kept all dps on Thanus. Adds werent an issue, druid had no prob with 5 on her, i just kept slowing everything in sight. Strong healers would be my recommendation to counter the AEs and the adds.
Also dropped Sleeves of the Moon (int caster arms), submitted screenshot this morning.
Not a raid mob, took him out with one Qvic geared group. He makes ice golems every few seconds that hit around 500, and are mezzable although very resistant. He also has a nasty DoT (Will of the Borne, 850 per tick). He doesn't have too many HP though, and doesn't hit very hard, best bet is to burn him down while kiting or mezzing the adds.