The last displacement applied is the one that overrides others previously applied. That includes self; just generally impossible if you're being displaced by an enemy. Only Ez, Kass, Leona (movement is delayed significantly with Zenith) etc work with it because you can't cancel their animations, so if you try, their displace occurs last, thus works.
Only melees I find myself winning with are Olaf, Irelia, Maokai, Malphite, and Mundo.
You might be able to do something with Trundle, GP, Fiora, Panth. I wouldn't know though, I don't play them.
If you time Maokai's Q right, you can cancel her Vault. Remember: the last displacement applied is the one that over-rides. If she's mid-Vault, you can pop corrupting, Q her, auto a bunch, W, Q...she'll be dead if you had ANY minions at all.
She won't get Harrier that way, won't get the vault damage, won't CC you, her blind will either come way too early, in which case you can W her and the rest doesn't matter, or she'll cast it after you W or Q...in which case it doesn't matter.
Use E to cut off her escape and you can probably land another Q for a kill if it hits+detonates.
Worst case, you can W her mid-Vault. It won't hit if you're in-flight. Try to use it to dodge her blind, though.
For Irelia, just play it super safe, stun if she's trying to harass you under tower. Ez Pz.
If a jungler ganks, she's 100% dead.
Olaf, just play safe and farm with Q spam. You should be able to live long enough to hit 6, in which case you win if you've been aiming Qs to hit her and CS at the same time. You will kill her before she kills you.
Olaf outscales her insanely hard. Just watch out for the blind. His ult doesn't cancel it...lol
