The mechanic
Galio's ultimate picks an ally up to 4000 to 5500 units away and lands on them 2.75 seconds later, knocking back the enemies around and shielding the allies in the area. The target has to hold position until he lands.
Why it needs saying
Same trap as Shen, with a longer flight: the targeted ally has to stay where they are for almost three seconds, at the exact moment everything tells them to leave.
When you play them
- team chat
what you type
ulting on you hold
in full english
I'm ulting on you, hold.
the context
"on you": the ultimate is cast on the ally, who becomes the landing spot. As with Shen, they have to hold for 2.75 seconds. If they run, Galio lands on nothing and the shield covers nobody.
When an ally plays them
- team chat
what you type
galio ult me i stay
in full english
Galio, ult me, I'm staying.
the context
"i stay" is the ally's commitment: they promise to hold their position during the flight. That is the half of the mechanic Galio does not control, and saying it out loud makes it reliable.