Base ability power increased. Ability power from activation decreased. Combine cost and total cost increased.
This item is doing alright on champions who can spam spells and get its active charged, but that number of champions is pretty small. Shifting some of its active's ability power into its base statline should make the item slightly more accessible.
TOTAL COST :  ⇒ 2900 gold
COMBINE COST :  ⇒ 800 gold
ABILITY POWER :  ⇒ 120
ABILITY POWER MAX ON ACTIVATION :  ⇒ 80
MOVEMENT SPEED MAX ON ACTIVATION : [30%] ⇒ 50%
The more fighting, the better.
BUILD PATH : Aether Wisp + Needlessly Large Rod + 700 gold
TOTAL COST : 2800 gold
ABILITY POWER : 100
MOVEMENT SPEED : 10%
UNIQUE PASSIVE : Nearby allied and enemy spellcasts charge Spellbinder up to a cap (100 maximum)
UNIQUE ACTIVE : Gain a maximum of 30% decaying movement speed and 100 ability power for 4 seconds, based on charges spent (60 second cooldown)