There issue with class arch type. one In a player handbook a assaisin get poison people. there no fluff for class out line of PHB. It lacks balance, this class make you in effective in combat. It's all about balance it's not there. may i make a recommendation: add more to poison table in the dmg.. or try to rework this class

This is a great archetype for the rogue that is not over powered and is unique.

Thought this may be overpowered until i compared it to the assassination rogue and realised its not. I like the idea of the pet snake for poison milking and and increasing DC on poisons is clever. All and all it was worth the money i spent thanks.