I don't really want a more spammy ult on Kassadin
So, Riot is testing changes on the PBE which basically change Riftwalk like this: Range 450 -> 500 Mana Cost 60 -> 50 Cooldown 6/5/4
I appreciate that Riot is trying to fix the problem they caused when they nerfed the distance on his ultimate, but I feel they're going about it the wrong way about his ult, perhaps the wrong way they've been going about his ult all along.
The problem is this: ok, I have this teleport on a short (3 or possibly 2 second cooldown), which seems nice and all, but what can I really do with that? I have some of the lowest damages in the game (like support level damages), 2 of my other abilities are on a 9 second cooldown, and my other ability which is on a 6 second cooldown requires spell cast stacks to use while doing as much damage as my Q. I can only slow my opponent for 1 second, meaning that in order to chase them (especially if they have any mobility of their own) I'm going to have to ult to run after them, but what will I do then? Some marginal auto attack damage... I have this ult that lets me warp around a lot, but I can't actually do anything meaningful when I get to where I want to go...
There have been some people who have talked about sacrificing damage to get his old ult range back - I fundamentally disagree. Kassadin has sacrificed enough as it is for his mobility, more than any other champion has.
What would I give up for more power then? The whole thing about Kassadin's is that the nature of his ult makes him unable to be punished for his mistakes. As such the solution is simple: increase the cooldown. I would be fine with a 6 or 7 second cooldown at max rank if it meant that I could actually be impactful when I reached my destination - off the top of my head changes would be, increase cooldown of ult at max rank to 7 seconds, remove the shield from Q lower the AP scaling a bit and give it a mark which pops on your opponent for extra damage if you auto them within 3 seconds, lessen the cooldown on his W again, and make his E do extra damage to magic users (like veigar ult). That would enable him to actually do his job (killing people), reward him for staying in a fight (additional damage tied to auto attacks, or stacking spell charges vs mages), and punish him for screwing up (longer ult cooldown means no zhonya's escape pattern, no shield on Q).
A spammy Kassadin isn't super fun for anyone, not for his opponents who find chasing him akin to catching a greased pig, or for Kassadin who's offensive abilities are all super low impact. Take away the spam, and let him be more delicious instead.
God I'm hungry.
Someone try it out after he gets buffed.

Has a unit targeted leap every 4.2 seconds, an auto reset every 2.1 seconds, a 2 second defensive steroid which blocks all AAs and reduces aoe damage by 25% followed by an AOE 1 second stun every 5.6 seconds, a high magic damage proc every 3 auto attacks, and another defensive steroid which grants armor and magic resist every 56 seconds.