Evelynn's ult cd is insanely long

150/120/90 seconds! It's way too long for a spell that you need very often and is not as gamebreaker as other spells which shares the same cd( Amumu's, Nocturne's) and many other strongers ults have lower cd(Malphite's, Sejuani's etc...)

You find yourself everytime with 20-30s missing for your ult between 2 moments you need it and there's no way to change that because there's no cdr items you can get fast unlike other champions with high CDs and you can't get CDR runes/masteries.

The only cdr items that you can get on AP Eve are and that you usually take as 5th or 6th item wich leaves you with only 10% cdr for a least 30 mins.

You can also get but it makes you really really squishy for a champion with no gap closer, low burst and who needs to stick to her target a long time to kill. Evelynn has very low base HP so it's really hard to take something else than otherwise you get burst before you've done anything.

Finally, I think her ult's CD should be reduced, maybe to something like 135/100/75 to match better to what her gameplay actually requires: not too low in early so you can't abuse it in laning phase but way lower in midgame because ATM the moments you need it don't match its CD.