The problem here is that Hailscourge takes so long to attack you so going invisible doesn’t help.
Fatshark fixed that problem for Shade, Huntsman, Ranger and Handmaiden on Zerks and Monkeys with a workaround - these ults now apply a dodge state.
Hailscourge’s goo doesn’t care about the dodge state, so it still targets you even while being invisible if you only go invisible after he had already targeted you.
Someone needs to test if you can get targeted by him while already being invisible.
Doesn’t matter when you trigger the invisibility he targets you anyway. You can use the ult before he triggers goo, after, or during and the result is the same: he will turn towards you and fire it at you.
If you’re behind him and invisible he turns to look directly at you and fires the goo. Unless he can see all invisible characters I don’t think this is the intended effect.
We’ve passed this on. It may just be that he’s a bit of a wizardy Chaos lord who sees through cheap elven trickery but we’ll let the designers think about that =) thanks!