"Predestination."

I think it was still fairly new when Bishop did it, time-travelling on the old X-Men cartoon: Forge would send Bishop back in time, to stop domino 1 from falling and causing their nightmare future. Bishop would do so, come back, and the future would still be a nightmare, further aggravated by Forge now asking why he didn't stop domino 2 from falling. Bishop would go back, and sure enough, crappy future, way to drop the ball on domino 3, jerkhole. Short of removing a whole bunch of figurative dominoes at once, he's going to have a hard time changing anything.

That said, I have no idea what Marvel's rules on time-travel are now, post-Secret Wars. Perhaps rules should be in quotes there, I'm sure it's a crapshoot. Still, if a messenger from the future gave you detailed instructions on getting the future you wanted, as long as you didn't deviate from that plan in any way, no matter what; would anyone be able to do that? Few would be able to resist changing (or not changing, as needed) one little detail in there somewhere, and bam! Whole thing'd fall apart.