Basic asking:

Omnislash is too weak now.
Set it unstoppable like Troll Warlord, and only attack attackable targets. i.e. always last 3/3.25/3.5 (4/4.25/4.5) (5/5.25/5.5) seconds. if no attackable targers, jugg just can move freely, while attackable in range and Omnislash still remain some duration, juggernaut will automatic use Omnislash again.

For example, Juggernaut use Omnislash(4.5s) to a SF with SF's illusion, after 0.5s SF cycloned himself, jugg used 1s killed the illusion, then wait another 1.5s, SF is attackable again. Now, jugg continue Omnislash to SF for 4.5-0.5-1-1.5=1.5 seconds.