Helioskrill did not Unlock

I finished the MCC all on legendary difficulty. I looked at my achievements and the “Legend” has it listed 39/40. I reviewed all my missions on the games campaign and all have legendary completed emblems. What’s the problem? I got Helioskrill Warbound and decided to get the original but nothing. No achievement unlocked. No Helioskrill. Someone please help.

If you have used any skulls during your playthrough, it will not unlock Helioskrill for you. You have to replay any missions where you used skulls. Otherwise, I don’t know what to tell you.

I didn’t use any skulls. I didn’t want to risk it so I went the whole way through without them. All I can think of was a glitch that happen on halo 2 when I picked up a skull and it stayed in my hand like a 3rd weapon every time I switched weapons.

I never picked up a skull in Halo 2 and got helioskrill. That mighr be your problem. Whatever mission(s) that skull was on, you’ll need to replay that and you should get Helioskrill.