Talk:Kassadin/@comment-92.250.91.235-20120621142144/@comment-88.186.19.90-20120621182942

Its used to prevent him from being OP in lane, but still allow him to use it repeatedly in teamfights.

Because his burst consists of 2 low-cooldown spells (his nether blade is used to finish off opponents when they have 150HP remaining) with high damage, giving FP a regular cooldown without that "charge up" mechanism would make his DPS way too strong in lane: He would effectively burst you as strongly as if another AP mid had used his ultimate every 9 seconds from complete safety.

However, If we dismiss riftwalk as a DPS ability (until lategame it averages 150 damage without stacks, with kass's squishyness you shouldn't use it to damage), Kassa has no AoE damage for teamfights and no spammable spell, and unlike Leblanc or Talon, he cannot insta-burst his target before retreating to safety (you usually need a second spell rotation or to finish them off with nether blade); meaning that his teamfight potential would be absolutely null. Hence the low cooldown on FP that allows you to cast it twice or more in teamfights.