This is key as at the end of each of your turns, Captain N'ghathrod allows you to gain control of an artifact or creature an opponent milled that turn, potentially cheating your opponent's most powerful cards directly into play under your control
Not every game will give every player what they are looking for, but over the course of an evening, or even over the course of multiple play sessions, I think you want to make sure everyone is getting something positive out of the experience
Etrata, the Silencer and Ramses, Assassin Lord are perfect additions to the 99 that support the assassin typal theme and get as many combat triggers as possible
Instead, it lets you ask opponents if they want to pay two mana every time they draw a card
A big body that lets us use excess mana in the late game is a great thing for this deck
MTGs Bloomburrow set is another much-needed palate cleanser after the darkness of the Phyrexian Invasion arc