Lanaru the Mad
The demented consciousness of Lanaru the Mad is so twisted by rage that it has wrenched itself free of Rularuu. His psychic instability has manifested as a permanent storm that surrounds his castle and himself.
(credit to khaine_star whose work is included)
Lanaru is one of the hardest Archvillains that Heroes can face. It is recommended that you have a full team of eight to confront him.
Lanaru is surrounded by two rings of enemies - an outer ring of elementals, and an inner ring of Rularuu. Clear the outer ring without aggroing anyone else (easy enough), then have Lanaru tanked while you clear the inner ring.
Lanaru himself has storm powers - Hurricane, Freezing Rain, Lightning Storm, etc. On top of that, he can summon Cyclone Elemental bosses which can do powerful auto-hit damage (dangerous for the defense-based powersets in your team). However, as long as you can stand up to this, he actually goes down pretty easily. It is recommended that blasters, defenders and controllers stay at maximum range and attack while the tank keeps aggro and the scrappers divide their time between the Archvillain and the elementals when they appear. Ice tanks and Super Reflexes scrappers will likely have a hard time during this battle.
Lanaru has high magnitude Stun attacks which are directed at the ground only (Locational Area of Effect). If the melee types are attacking him from his waist up and everyone else is "flying high" or out of range he is much easier to beat.
Defeat Lanaru the Mad five times while in Supergroup mode and receive the Rikti Plasma Turret Badge Supergroup badge.