Trajann Valoris/Ann Valoris

Ann is the current leader of the Custodes in the year 40k. In the original universe, Trajann was the most powerful member of the Imperium after the Horus Heresy until Roboute's return. In this universe she's never been the strongest in the Imperium. However unlike her canon counterpart, she's a Chaos Custodes. So she's even more powerful. On par with the Primarchs.

During the Blood Game's, only the best of the best Custodes ever make it through the palaces defences. Not only has Ann done it once, she's the only Custodes in history to ever do it twice. She also has many great victory's under her belt. She destroyed the Space Hulk Mournful Siren. She defeated the Genestealer Cult Empresses Writhing Shadow. She spear headed a preemptive strike against the Ork WAAAGH! Krushfist. The list go's on.

She dislikes impatient people, but she despises those who do not take action because they believe their effort would be better spent on a "more important battle." She is worthy of all of her acalades and then some.

(Sorry. On YouTube I can only find videos talking about fights he's been in and how powerful he is. Haven't found any that talk about what kind of a person he is or any humanizing moments. If you know any video's like that, let me know in the comments.)