Saint of Killers w. Genesis replaces Thanos......

This is the Saint of killers merged WITH Genesis-
https://static.comicvine.com/uploads/original/0/9116/1519168-preacher35.jpg
https://static.comicvine.com/uploads/scale_medium/0/760/86634-121325-genesis.jpg

he takes thanos's place during the infinity gauntlet saga [only difference is that the living tribunal CAN intervene if necessary].

How does this go?

sok solos Marvel

We all know about SoK's revolvers:

The only exception to that rule, however, is Cassidy... He survived a shot from them:
http://i.imgur.com/mGKdvuQ.jpg
http://i.imgur.com/PJo3Onv.jpg

Although in a later interview, Ennis did say that Cassidy surviving was a mistake -- he was still trying to feel-out SoK at the time, and that scene was written before he came up with the backstory of SoK's revolvers... Which does make sense, tbh, as SoK was originally released to kill Genesis -- a being with power no less than equal to God himself:
http://i.imgur.com/SsAit2h.jpg
http://i.imgur.com/f8vtA1B.jpg

In fact, it was implied that Genesis was even more powerful than God... To the point that God literally fled Heaven in fear of it:
http://i.imgur.com/qxy3mj5.jpg

...And obviously an entity =/> God >>>>>>>> Cassidy. So yeah... srug

Anyway, while I'm not at all sure what'd happen here, I do know that SoK's biggest asset(in terms of reliability) is Genesis. It is basically Ennis' version of the ALE -- seemingly able to overtake/manipulate/control ALL.

How fast is the SoK?

I.e. how fast can he speak or move his hands to draw and fire a gun?

No clue.

In the series he was immune to all physical harm and his bullets always hit their mark -- so he never really needed to 'out-speed' his prey. /shrug

Didnt SOK also kill god and the devil? im sure no one would try to argue that cassidys durability is better than theirs LOL.

Indeed SoK did kill God:
http://i.imgur.com/JhXY9Iu.jpg
http://i.imgur.com/T1GyCLu.jpg

But in the Preacherverse, God is only fully omnipotent/invulnerable whilst sitting on his throne in Heaven. When *not* seated on the throne, however, God becomes vulnerable/killable. This was originally postulated by Jesse:
http://i.imgur.com/QPzttbt.jpg

And then explicitly confirmed by SoK himself:
http://i.imgur.com/vXOTXYS.jpg

That said, SoK *did* kill Satan outright with no stipulations, and made even the Angel of Death shit himself in fear:
http://i.imgur.com/wPLw5aD.jpg
http://i.imgur.com/YV38X39.jpg
http://i.imgur.com/ipvW2v0.jpg

So yeah, your point still stands. 👆

Tbh, I think it's obvious that Ennis had a huge change of heart/thought regarding the capabilities of SoK and his revolvers in the 1+ year span between 'Preacher' #3(wherein Cassidy survived a shot), and the 'Saint of Killers Special'(wherein the backstory of SoK and his dues ex/haxx weaponry were officially canonized.)