ShiKage's Infighter Build

Vipers don't get 2hko'd. They have a good amount of hp, enough to take around 4 hits from most of the high level monsters they'll be training on. Drain seems pretty reliable to me.

They can be. If a level 130 Viper were to train on monsters, such as skelegons, which hit more than 3k damage, then they're very easily killed. Remember, we don't have nearly as much HP as Warriors. We have around 1.5 - 2k less HP.