No, just nerf them, so they are healthy for the sake of this game.
Examples of a few healthy and balanced champions:

Those are just a few examples.
My suggestions to bring them to the balanced line:
Kalista - Slows are now affected by the distance of her passive. E's damage is capped at 300 against jungle monsters.
Vayne - Flat true damage removed. Attack Speed per level reduced to 3%. Tumble Mana cost increased to 50/45/40/35/30.
Jinx - Fishbones no longer deals 100% damage to all enemies in an area of effect. Now, secondary targets take 75% damage (primary target still takes 100% damage).
Sivir - Movement Speed reduced to 325. Spellshield now costs Mana, but refunds twice as much mana as now.
There, balanced.