Christian into this Del Rio vs. Edge feud. I know we all aren't Christian fans, so I'll rephrase the question a bit. If Christian had to be inserted into the feud, what would be the best way to incorporate him.
1: Teddy Long straight up adds Captain Charisma to the match.
2: Christian feuds with Del Rio for the next two weeks, but ultimately puts over Del Rio so he could go into Mania strong
3: Christian acts as special guest referee for their Mania match, the WWE could plant a seed of doubt and create a rift in Edge's relationship with Christian to add intrigue to the match. Or WWE could make it seem as if Edge and Christian are back as a team, but Christian screws Edge immensely at Mania.
4: (If mitb is held) Christian could be a thorn at the side of Del Rio just to keep him relevant in the story. At Mania Christian would win the Money in the Bank match and Del Rio would go over Edge for his first world title reign. So then all have a legitimate shot against each other, with both Edge and Christian guaranteed a world title shot.