King should be able to counter Hellblaze with Sunflower or simply move out the way. And King too is extremely durable and agile. And he can fly, giving him a spacial advantage. As for teleporting, he might not be able to teleport other things, but he seems to be able to teleport himself over short distances. That or his speed surpasses even Ban and Mel by far, as seen here
Plus, so far it seems that full counter only works against blastlike attacks, so he may not be able counter King hitting him with full force with Chastiefol's spear form, or worse, guardian, which even immobilized Ban, and still works for attacks. The clones could help Meliodas out, but King could easily keep them occupied, or even destroy them with increase. On the other hand, if King messes up and lets Chastiefol get hit by hellblaze, it might get destroyed, leaving King at a huge disadvantage, unless he uses Disaster or something. Like I said, both could find ways to beat each other.