I think Diana needs her R changed into a skillshot/targeted area type spell

Diana, in my eyes, is in a hard spot right now because she is one of the least mobile champs in the game. I know, you're all thinking "her ult is a gap closer, on short CD, that can be reset". Yes, that's true. What's also true is that she is a melee champ with caster movespeed, she's very slow; and her gap closer, because it is targeted, can only be used to engage, but not disengage. The end result is an Akali like assassination style, but with no way to disengage afterwards. Diana is stuck in the fight once she's there; and for a slow footed champ with only a an AP scaling shield to cover her back, that's a bad spot for her. In the current state of LoL, champion mobility has powercreeped beyond just having a gap closer, or a single MS buff. Now, mobile champions are defined by their ability to both close gaps to engage while also having the ability to create gaps to disengage. In this regard, Diana suffers a lot.

If her R were changed to target an area, or be a skill shot, then it would create a combo that gives her an "out" from jumping into the fight as she would be able to reset the CD on her R and use it to disengage. This further rewards Diana for landing Q prior to landing R, and it has the opportunity cost of more damage or leaving the fight for the second use of R.

It would be a good change to a currently mediocre AP assassin.