When Nocturne ults an enemy champion, if this one has a high speed and leave the place where Nocturne ulted the target, it will stop at the same spot where the enemy champion was, meaning theres no chase.
1. Pick Nocturne as allied and any champ who has a high movespeed skills (such as Rammus, Hecarim, etc...)
2. Get to level 6 and ult the enemy champion. As an enemy, youll have to run away as fast as possible when Nocturne is coming after you
3. Nocturne will stop at the same position (or very close to it) where he clicked the enemy champion to use the ultimate
- This bug may be affected as well with champions with leaps and jumps such as Tristana W or Leblanc W, meaning that Nocturne cant have a good chase-up to those targets.
- If Nocturne is relatevely close to the target, the target will receive damage from the ultimate, but Nocturne will not be on the same spot. This applies that if the target is far away, it doesnt receive damage from the ultimate
Credit to "Ate my OWN A55" for finding that out