Can Kassadin get some love, please?

Like, he's got some major issues.

First off, he's melee and his only defensive ability only shields magic damage for 1.5 seconds and is on a 9 second cooldown. Secondly, his ult damage scales with mana. And its only 2%, up to 10% if he spams his ult which drains mana so fast. With a fully stacked RoA and Tear, along with base mana at level 18, he can only use his ult 7 times before he runs clean out of mana, and that's not even counting his other abilities. Although he can use his W, it still, even against champions, only allows him to Riftwalk 1 more time, and use his Q once and his E twice(assuming he actually gets all those spells around him to E twice, let alone the cooldown before he can, but that's only 6 seconds).

So basically, with his ult and a fully stacked RoA and Tear + level 18 mana he can deal 186 magic damage with the first riftwalk, then 280, then 373, then 466, then 560. Then he can ult 2 more times with those stacks before he runs almost out of mana, only allowing for one more Q then E, and allowing for one more Riftwalk + Q and two E's if he hits a champion(not a minion, champion) with his W.

I personally think his mana costs should be lowered for his R, at the very least. The very least, if not change his Riftwalk ratios to AP instead, or at least raising his other ability's ratios. I mean, with his whole kit, he basically deals 210% of his AP(might be -10%, if Nether Blade's passive doesn't trigger when using the active), and 490 damage, minus his ultimate. With his ultimate, at full stacks, then he would deal 360 damage + 10% of maximum mana.

Maybe I'm just underestimating Kassadin, but even seeing him in Urf was kind of lame. Even with spamming Riftwalks, no mana, and not worrying about building Tear of the Goddess, he seemed kind of underpowered, or at least, comparing to all the other champions.