KSI says Dillon Danis is persona non grata at all future Misfits Boxing events ... telling TMZ Sports if he ever sees the MMA fighter again, he'll "probably slap him in the face for all the disrespect he gave me."
As we previously reported, Danis backed out of his fight against KSI just days before the event was slated to go down in London ... with Misfits promoter Mams Taylor claiming his team told him Conor McGregor's buddy was underprepared to enter the ring.