Let's talk about the 800LB gorilla, Vaal Gems

A few are very useful, you're just a noob if you don't see the potential.
*cough* Molten Shell *cough* Dominus... incinerate...soul beam... whatever it is. All I have to do is use Vaal MS and face tank his beam of souls and he kills himself in less than 2 seconds... And.. yea, basically any other boss fight Vaal MS destroys.