Add and remove buff

[DexterFstone]

Hi I'm trying to make ult Jaina it's like DotA map and make a spell to add slowing for the area of ult

but how to do that? (when unit move to the area of ult add a slow buff and slow MS AS and when leave remove buff and remove slow MS AS)

 

[pr114]

You add a negative endurance aura to a dummy unit and move it to the position of the caster.

 

[Uncle]

For a more precise design you could turn on a trigger that runs let's say every 0.25 seconds and in it you pick and slow nearby enemy units.

The slow could be handled with a Dummy unit that casts a movement slowing ability (Slow comes to mind) on the picked units.

You make the duration of the slow something short like 0.25 seconds so that when the enemies leave the freezing field the buff will wear off very quickly (at most it will linger for 0.25 seconds).