Assault

Assault triggers if the engaged champion uses an ability to relocate itself, but not if it's relocated by another champion. So Teleport and Leap will trigger assault, but Relocate Ally or Knockback will not trigger Assault.

Swap (the ability) is another interesting example. If the champion using Swap is engaged to the Assault champion, it will trigger. If the champion being swapped with is engaged to the Assault champion, it will not trigger.