How to fix Rylai's

Give it a single target cooldown, like Yasuo's E. Give it a 3-4 second cooldown per target hit. For AOE spells like Viktor's entire kit (minus his Q), have it be the same thing, just applied to all targets hit. I feel like this gives a more fair chance to run away or dodge skill shots after a given time and people like Syndra can't just perma-slow you.