BLAST VS VOID LET'S GET IT. There would be nothing wrong with Blast getting hurt in my honest opinion. Void has tsken cosmic garou's powers snd established to be on par with Blast. If anything, it wouldn't make sense for Blast to be unscathed.
Blast were once defeated empty void in the past 15 yrs after her received the power from god which leads to him a advantage over blast in the fight but blast nearly killed him and puts him coma for 15 yrs But what we have seen so far blast didn’t demonstrate his full capabilities nor empty void in current time but it could be the time for now to see their full abilities Tho I might say blast would win due to his narrative role to play in the future along with his son introduction and his relationship to the inter dimensional friends and his history with god Since it’s fight between partner we could expect them to be at least par on in some stats but one should be stronger at the end without saitama getting intervened