Ram's Voice locks in more quickly than the cast bar indicates. This is true of all Chimera variants, including those in POTD and HoH. It also applies a powerful ice DOT. Take the suggestions offered in thread, and stay outside its radius, move in when it's Dragon's. Simplest solution.

It also has another attack, Ram's Keeper or something like that, which has a circular telegraph that drops an ice puddle. I don't think that's what's killing you, but if your ping is really bad, you may be getting hit by it too.