A Quick Suggestion on how to Hurt Kassadin in Lane, but Retain His Lategame

Patch 5.3's notes on Kassadin for reference; http://na.leagueoflegends.com/en/news/game-updates/patch/patch-53-notes#patch-kassadin

You keep mentioning how you want him to have meaningful weaknesses, and you've succeeded for the most part with the hitting of his ult's stacks to 20 seconds. You do need to put a lot more thought into Riftwalking since that change, and it's been shown. However, you mention wanting to hit his laning, but not in a purely unhealthy way. While this seems complicated, why don't you just do what you've done with some recent champion redisigns/releases? You could easily just cut the damage on his QWE (ult does pitiful damage as is, no need to cut that) but give him it back gradually with ranks in his ultimate as a passive, a-la Sona rework/Gnar balance treatment. I feel like this would be perfect for retaining his role as a lategame god, but hurting his lane. For example, say you were to cut 20 + .2 AP from all 3 skills. But you'd give him 10 + .1 AP per ult rank to those skills (slightly stronger lategame, but it's to reward you, give and take, as this is a pretty huge nerf to his early game). Not saying those are the exact numbers you should use, but I think it would be a great way of achieving the goals you're shooting for. Also I'd make Q's damage in line with E again, just to make it cleaner. Too used to seeing them be the same.

Thoughts on this? I mean, considering how well the stack drop-off nerf worked, even that could potentially get worked into it. Instead of it being a 20s dropoff at all ranks, it's 25/20/15 (again, just theorycrafting this). NOTE: I'm NOT hitting his utility of his Shield on Q (could get buffed, IMO), mana restoration on W and the slow on E. Also W's passive needs to stay as-is, because it'd be nice to AT LEAST last-hit. If you remove literally everything he has until level 11 it just gives an excessively negative experience.

How skills would look with theorycrafted numbers for reference:

Q: Null Sphere Magic Damage: 60/85/110/135/160 (+10/+20/+30) ((+.5 AP)+.1/+.2/+.3 AP) Shield Strength: 40/70/100/130/160 (+.3 AP)

W: Nether Blade Passive Bonus Magic Damage: 20 (+.1 AP) Magic Damage: 20/45/70/95/120 (+10/+20/+30) ((+.4 AP)+.1/+.2/+.3 AP) Mana Restored: 4/5/6/7/8% Missing Mana Mana Restored Against Champions: 20/25/30/35/40% Missing Mana

E: Force Pulse Magic Damage: 60/85/110/135/160 (+10/+20/+30) ((+.5 AP)+.1/+.2/+.3 AP) Slow: 50/60/70/80/90%

R: Riftwalk NEW Passive: Grants Null Sphere, Nether Blade, and Force Pulse's actives +10/+20/+30 (+.1/+.2/+.3 AP) Bonus Magic Damage, based on Riftwalk's rank. Magic Damage: 80/100/120 (+.02 Maximum Mana) Bonus Damage per Stack: 40/50/60 (+.01 Maximum Mana) Stack Duration: 25/20/15 Seconds