Spoiler warning for end game content.



For the achievement "Honorary Uce" you need to gain Roman Reigns as an ally in the "Allies" tab, in order to do this, you need to complete all the other side missions until you get to his side mission. You'll know when you've unlocked his side mission because Paul Heyman will message you on your phone, that or you can check the allies tab and you'll see his picture at the far right. He will ask you to do a handicap match against both Jey and Jimmy uso, at this point the match should be easy as you've got your stats up a lot, and that's about it you just have to beat them to unlock the achievement.

While doing this achievement you'll run into a John Cena side mission as well far right, next to Roman. In order to unlock Ezekial as a collectable, you will have to beat him and Elias in a handicap match, not only will you unlock Ezekial as an unlockable fighter for all modes, but you will gain John Cena as an ally to fight for you. (There are other characters you can put on your team, but Roman and Brock are the best and will give you the most help for the upcoming WarGames match)

That's about it, pretty simple.