Nihilus' drain in comics is presented as a dark cloud(in color like the Dark Exile's drain), but in the video-game it has the orange yellow-ish color: 01:08
2. Nihilus' drain is stated by Kreia to be an ancient Sith technique that must be experienced at first hand; and that's the ability Nihilus uses. But during the game and even some sources, it was established that Nihilus can use the Killer-Force technique because of his Wound in The Force status and that he chose the dark side.
"He is a wound in the Force, more presence than flesh, and in his wake life dies… sacrificing itself to his hunger." ―Visas Marr
Only way for these inconsistencies to make sense to me is that the entire Triumvirate of the Sith(with Traya atop) were a bunch of Wounds in the Force who severed themselves from the Force(to become undetectable: sort of Yuuzhan Vong, eh, almost) or found a way to combine Force drain and Sever Force(a dark side variant of it) and created Killer Force(by studying the ancient Sith teachings)
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."