Need help deciding

Okay, so I have 235 RP leftover from my last purchase, and i plan on getting 1100 more rp which leaves me at 1335. My choices are to get yasuo who is on sale for 50% off plus midnight ahri skin with the leftover RP. Or get yasuo and wait until azir or zac come out on sale (which is during august)

Extra note: i main ahri and prefer to play assassins which is why yasuo is a definite yes either way, thing is that im not sure if skins are worth rp or if i want to try changing my playstyle with azir or zac. I could also get just one champ, but yes, suggestions on what to do?