Koseko, Shield of Demacia
Koseko's auto attacks deal no damage. Instead, they apply a stacking slow to their target. Koseko's auto attacks also execute minions below 80-500 health (Based off of level)
Koseko generates an aura around him, dealing magic damage. When the aura releases, Koseko deals 5/6/7/8/9% of his health as magic damage, and snares any enemy champions.
Koseko raises his shield, reducing damage taken from in front of him by 10/20/30/40/50% and shielding himself for 5% of his maximum health for 1 second.
Koseko charges forward, gaining a large burst of movement speed and causeing his next auto attack to stun the target and deal damage.
Koseko rams his shield into an enemy champion, silencing them for 3 seconds and damaging them based off of Koseko's MR.
(Post will be updated as I come up with more champ ideas)
Witch doesn't gain movement speed from % movement speed increases. Instead, those % movement speed increases increase her AP by a flat amount.
Witch extends her cane, smacking all enemies hit and snaring enemy champions briefly.
Witch channels briefly, bringing up a cauldron. Allies who are within range of the cauldron gain increased attack speed and flat movement speed, whereas enemies within range are slowed and take damage over time.
Witch sends out a bird that flies a short distance, then stops moving, granting vision in the area for a short time. Enemy champions can attack the bird to make it fly away
Witch smacks her staff onto the ground, causing black ground to spread from her outwards. (Will spread organically, moving around terrain. The ability will always cover the same amount of ground, so around terrain it would spread further out, but in open areas it would have less radius.), increasing all allies movement speed, AP, and AD by a %.