What should the save DC be. Personally, I think it should be around 20. Yeah, berserkers should be able to fight until they reach -10 in a berserk state, maybe even until they reach -15 or -20(Ignoring death until the berserker leaves it, like Orson in episode 7 of the TV series). I think +2 to strength or con isn't enough though, and it should be +6 strength and +2 con(To represent the awesome power of a berserker.) I would also give the template a -4 charisma penalty that can be stopped by the berserk state being sufficently controlled(Maybe no raging for a month would do the trick). I would say a will save can be attempted, with a DC of 30 to expel hyuri, the spirit of anger, but natural 20s are not treated as successes automatically, and it can only be attempted once a year, and only after a recent big conflict of interest(Such as trying to kill someone in your berserk state that you care for greatly). The spirit of anger will return, if needed, but only death can expel it afterwards. The berserk state lasts 10 minutes(Not sure if this is good, or if it should be longer or shorter), and leaves the creature fatigued(-2 to dex and strength, can't run, probably something else I forgot about being fatigued as well). It will also end if all life other then the berserkers own that it can see is extinguished.