This is a massive stomp.
Izuku's can only reach 12.71 Exatons with Fa Jin charges. While Reinhard is beyond that level normally, in fact he's 2x above Izuku's strongest attacks. And Izuku will need to charge up Fa Jin anytime he wants to unleash power like that, and it's barely going to do anything to Reinhard even if he stands still and lets himself get hit.
Reinhard is over 10x stronger than Izuku normally, which is more than enough for him to tank and one shot the second the fight starts.
Even if you equalized speed, Izuku cannot take Reinhard down due to the massive stat advantage alone.
This is all ignoring his combat skills, along with his power and abilities. Reinhard out skills and out haxs Izuku by such a massive amount that it's not even funny.
Yeah, I just repeated my same argument for when Cecilus stomped Izuku.