The Ken-Sun were a 3.5 monster from Monster Manual V, one of three "Elemental Mages" . All of them seemed to be heavily influenced by the Oni, and when I was looking for a mini boss for the Shnecke's Wolves game, the Ken-Sun (Air) version seemed a perfect fit.
Unfortunately, as is often the case, this awesome monster has never been officially updated to 4e, so I was forced to bring it over. This is what I came up with!
(As always, the modifiers shown after the stats do not include 1/2 the monsters level - so its Constitution modifier is actually +11 not +5)
(Click to summon the storm)