My pm reply to someone asking the same question, might as well post it here:
Base build would be something like that:
RoR.builders - Knight of the Blazing Sun
Switch tactic set with absorb for one with Focused Mending for 6man/wb. Auras resists/ap, and switch the last one depending if you need dmg (aoe dmg aura- dmg really adds over time), healing (when channeling htl a lot, or in team/wb in general), On Your Guard. Remaining points based on personal preference (might want to get Coordination from middle tree at rr60).
This gives you:
-Decent base defense from Rugged/absorb or extra healing from Focused Mending.
-Between ap aura and Perseverance+Sun's blessing, lot of ap regen. Which is useful for:
-Defense- when facing destro ranged, this will help a lot with channeling htl with no downtime.
-Offense- from experience on chosen, you don't really have a burst anyway- you kill with high pressure over time, meaning ap regen to keep pressure up gives you more than some extra dmg. Precision Strike+ Efficient Swings+ap regen+ws talis will give you just that. This while remaining snb, since chosen/kotb scaling with str sucks anyway.
-Shield of the Sun when combined with Sun's Blessing over time will add quite a bit of dmg as well.
-Semi burst- build up all your dots on target, then hit m1 for armor debuff/1 more dot and spam Precision Strike. Between 25% armor ignore and 1 k armor debuff from m1 thats when Precision Strike should start really hurt.
"Can we play with him, master? He seems so unhappy. Let us help him smile. Please? Or at least let us carve one on his face when he stops screaming."
— Azeila, Alluress of Slaanesh