Umm... you want to unit to simply stay and be unable to do anything? Ok, it won't be multi-instance though since you will need a local variable. Base the spell off rejuvenation with different buff and stuffs. Duration to how long you want to spell to last.
So, make an array unit variable with 16 positions. Now let's see.
Event - Unit - Starts effect of an ability
Conditions - Ability being cast equal to "yourability"
Actions - Set EntagleTarget [Player number of (Triggering Player)] = Target unit of ability being cast.
- Wait for condition (Entagle Target [Player number of (Triggering Player)] has Yourbuff equal to true checking every 0.10 seconds.
- Pause (Entagle Target [Player number of (Triggering Player)]
- Wait for condition (Entagle Target [Player number of (Triggering Player)] has Yourbuff equal to false checking every 0.10 seconds.
- Unpause (Entagle Target [Player number of (Triggering Player)]
This is a method. Hope it helps you.