yeah, there's a thingy called a scuffed roll which is essentially just doing a frame perfect crouch roll after a near perfect horizontal slash, if you do that then zero gets kicked out of the roll early and so you can then roll again.
@@user-se1ne1xm9n please don't, this is pretty much a TAS only strat (and also if you wanna find out more about the tech go to the game's speedrun.com website and look at the resources page)
It's called a ricky boost, if you deflect a bullet and bonk on a ricky frame perfectly then you will be flung forward, this can also exceed the normal speed cap
He is utilizing the ingame speed running mode with the actual story skipped. If you haven't played it yet, please do. It is one of the best games ever made :)