Hi everyone I discovered what I think is an undocumented glitch that can be useful for speed running.

Basically, I found a way to make a unit permanently invisible. This is extremely useful for story-required levels as you can have a unit just run to the end (including the final mission).

I was able to replicate this glitch multiple times on the final mission.

Make sure you're on impossible difficulty. (Just for a higher chance of a unit becoming panicked).

Have your ghost unit be one with a weak Will.

Turn 1 activate ghost and run all the way to the end where the overlook is. Have another unit stop beside them. End your turn. There is a Sectoid Commander you want to mind control your non-ghost unit. Save, and end your turn. Sometimes this happened on turn 1 and sometimes took a few reloads before they would mind control my non-ghost unit. But when my non ghost unit got mind controlled my ghost unit would become panicked. At the start of my next turn, my ghost unit would not get revealed and would remain in ghost mode for the remainder of the mission. Nothing would break me out of stealth including firing my weapon.

I was able to take this unit, sprint them to the end of the level, and kill the Uber Ethereal all while keeping my remaining units at the landing pad. Ranged attacks will never target them. However, melee units like Berserker can and will attack your ghost unit if they get into melee range.

I have no idea if the stealth will remain in effect after the mission ends since I only tried this on the final mission. I suspect it MIGHT because even during the cutscene they remained in stealth