In my last WoD today I had a fellow whm who would literally only cast stone skin. I get using stone skin on a tank before a big hit but he was just stone skinning constantly. His gear was mostly 90 and in the end it felt like I solo healed the whole raid. The 8 of us almost wiped on several occasions but we got lucky. There are times when stone skinning the whole party mid fight can be useful (xande during the meteor part) but sch are mitigation healers. Whm are healer healers.
