As posted on October 24, Ugnof Toestubber and party can take out characters easily; however, what isn't metnioned is that they go on patrol, chase you into town, and have changed targets in town. I was hacked down at 13th level while making a purchase. Just be carefull!
Another good place to hunt for people in their teens is the plateau area next to Huginfell (behind the Blodfelag Camp). Savage Lynxs, Black Maulers, Skogsfru and Wind Sprites roam that area. Lots of orange and red for a level 13 character. Always blitz the Sprites -- they have a powerful DD that can almost one-shot a mage or rogue in their teens.
The Blodfelag Camp across the lake from Huginfell is a great place for a group of 5-8 in their teens to make xp and loot. Make sure you have a good crowd controller, the Blodfelags spawn in bunches and are social. Look out for Ugnof Toestubber; he spawn with a Henchman and a Warhound. If you are disorganized he will smoke you (probably level 16 or so).
Huginfell, in the SE corner of West Svealand, is a great place to hunt up into your teens. During the day there are many grass snakes, grass cats, ribbon toads, large sveawolves, mindless thralls and blodfalag oathbreakers to fight. The maulers can be especially dangerous but yield some very nice xp in groups. At night this area becomes a great place to make money. Shadows spawn in great numbers, are yellow/orange at levels 10-11 and drop very respectable loot. You'll be piling on silvers in no time with these.