So if I'm reading Koggy's new W right...
Taking into account that his attack speed is doubled, Koggy effectively deals 90% of his total AD in physical damage, 2.5% of the target's max HP in magic damage per 100 AD, and doubles the strength of his OnHit items.
I'm guessing this is to force him to pick between running a raw AD build (which would let him annihilate people with his Ult) and an OnHit build (which means much weaker Ult)?