Soloed this tard twice, worst part was first time I wasn't paying attention an' let him gate on me an' summon me over to the kriger... ouch... still got him deaded. Dropped staff *grumble* once an' leather boots 2nd time. Pretty easy fight, ended 2nd fight (when I didn't let him gate an' get mehself jacked up be the kriger) with nearly full hp an' 35% mana or so. Max hit I noticed was like 600ish, didn't hit too fast. No enrage or flurry or nothin's.
Soloed easily with my Enchanter (Trevor), just send pet in, Tash, adn slow until stick. Trust me you won't get agro from pet. Have to use a Militis or Kriger tho (I use Militis, Kriger break to fast). Give full set of Mage gear (two diff weapons seems to work best) and Speed of Vallon. I usually NDT then also to increase proc rate and add alittle more DPS. Be prepared to spam the /pet back off button on enrage tho. Best to pull hit guards and then sic pet on him to avoid getting agro on yourself. Thanks for the Ring of Thunderous Spirits, I already have one... And that Ring of Torden is just uber!
Ymir Stormseer is located in the Middle South camp. He is a caster and will gate, max hit was 607 and lowest was 303. Very very easy to kill as he casts alot and doesn't melee very often. He dropped 2x Jord Meat and a Greatstaff of Thunder when I killed him.
Ymir Stormseer spawns in the Middle South (Right Side) area behind a set of tables. Thangbrand (the wolf) also spawns right next to him. Krigers are their Placeholders.