King > Rooftop Zoro > Killer.
Giving Killer the benefit of the doubt, King mid diffs.
He'll bombard Killer with Wind Scythes and fire bullets while flying around him. Once he spots an opening, he'll nuke Killer with Tempura Udon.
Fire Bullets are low arsenal, never highlighted for effectiveness.
Killer is a master in deflecting, King's Wind Scythes may have an higher ratio but ain't impossible to deal with, Killer would be giving the favor back with Kama Sonic since King needs to come in range to really be effective.
Killer's Kama Sonic covers 360°, no blind points, unlike Zoro's Pound Phoenix attacks. Also bypasses King's best strenght: tough hide due to his Ancient race + Ancient DF, doing a better job than Tatsumaki.
Tempura Udon is slow af, King had a point blank opening on Zoro in this chapter and barely brushed him.