Practically one shotting people with her passive + autos. I don't think 100% critical strike chance items, even for one attack should be allowed in League of Legends. It's extremely busted, and I love Riven, but she should not be using this item. With Death's Dance it makes her autos heal her for insane amounts as well. At the very least if you allow Stormrazor to exist, make Death's Dance unable to heal from critical strikes.