Ok for all of you that are having trouble with unlocking the hayubasa armour do not be afraid, because I know how to unlock them and I will tell you all about it.

Hayubasa Helmet - Unlock all of the skulls.

Hayubasa Body - Unlock 5 skulls.

Hayubasa Shoulders - Unlock 9 skulls.

That is how you get the hayubasa set and now for the people that are having trouble with the IWHBYD (I Would Have Been Your Daddy) skull. Ok, first select the level the covenent on normal, heroic or legendery diffuculty. (For all skulls you must be on the normal, heroic or legendery settings.) and now for the ~~~"how to get"~~~ the IWHBYD beat the level from the start to where you get to the room with 7 rings, 1 is at the start of the room 7 is at the end of the room. at first the flood apear to be on your team first kill the prophet. then kill all of the flood to avoid interuption. now jump in the rings in this order : 4654534 and then go back to the bridge near where you killed the prophet, it should be right smack in the middle of the bridge. the logic of these number of rings is because each of these rings plase a note from the halo 3 theme song and this order produces the notes of the end of the theme song. So yea, I hope this helped, I'm sure there is some videos on youtube.com but this is just a writen explenation. sorry if i did a bad job of explaining it. ps. if you did the combonation right then the rings should start lighting up from 1 - 7 rapidly and then you know that the skull has to be there.