Oh, I guess if Embryo at 2-A's OP enough to bypass a bit Tier 2-A, I guess maybe you're right. Tho, I just wanna add that Meng Hao can do/resist mmore than the 8 there. Rapidly skimming throu those you listed and mentioning the "main" ones, Meng Hao ignores Time Manipulation, and I don't think Memory Manipulation would work somehow with his 7th hex, but even that aside Meng Hao has a feat of resisting a 1-A level Memory Manipulation, so there's that with Memory and Mind manipulation. Anyway, all Time-Space stuff won't work, since he's immune. Existence erasure won't work. Same with Corruption/Corrosion, MH's as a quasi-Demon's already corrupted, on top of having Regenerationn and stuff (and if you could please tell why Embryo negates immortality and regen it would be great. No need if you can't/don't want to, I'm not looking for a debate anyway XD). With Meng Hao's 2nd Hex Real-Unreal reality manipulation and stuff like that are out as well. Karmic Hex and Life-Death Hex also let him control(and also resist) all related subjects to those, so there's that too.
Aaah I wrote more than what I wanted, too lazy to continue T_T.
Just know that MH's profile is also not quite finished, so stuff could be added or removed in the future. (and honestly I dunno why so many resistances are missing, since basically there if he basically control smthing he can resist it, as he showed with his Karma/fate stuff. Welp, must be cuz I'm a newbie here, I don't get much of how it works here XD). So there's that.
And I don't know much about Embryo tbh, so I dunno much. You make it sound like Embryo has a high chance to win tho, so I'll believe you at face-value for now, I don't wanna debate here after all XD. And since Meng Hao also got Immortality 1,2,3 and 8 at that time, along with what I listed here, I think it's rather more of a "tie"
Anyway, have a nice day

. Forgot my goal here for a sec.....tho, if nobody else comes here and you wish to continue in the future, I'll be happy to oblige when I have time irl.