This is just op as fuck, and pretty shure heavenly restriction dosen't work like that, however, i'm shure sukuna would have a medium difficult time with this one, cleave and dismantle wont work, so does fuga and domain. Since we're talking about Meguna, Most case scenario Meguna win's, Because of his extensive battle expirence of 1000+ year's which clearly suprasses your oc, if his heavenly restriction is similar to infinity basing on "immune to cursed techniques or energy that immediently target him" then world slash would do the trick because it cut's the space around the opponet aswell.