yeah phase rush seems kinda troll. Galio is about getting in and doing his stuff and then doing nothing (his cds on everything but his passive/q is terrible). Id only really consider it against someone like nasus who has an insanely strong slow or enemies that you want to run away from after doing your combo (like illaoi so u dont give her free tentacles for r) or whatever.

phase rush would be a bit better in lane due to allowing short trades and then running.

Thanks for the input, glad you liked it, I enjoy predator for consistent Ganks after first back since you pretty much need move speed through ghost or pred to gank effectively and I use ghost before first back for an early kill bot typically.
Personally I find phase rush as an odd rune for Galio since after you proc it you dont really need the move speed, so I prefer Pred for engaging if that makes sense. I'm open to trying it in the future just with a tank and slowing build I dont know if it would have a lot of value.
Aftershock was what I used starting off, but since I mainly engage with W which would proc aftershock, I dont really need the bonus resistances from the dmg reduction on W, but again open to test it more.
Currently I am doing quite well with the pred build- Frostfire-demonic-zhonyas- FoN mainly because Galios w scales with ap better than mr so ap/resistance items are pretty good compared to full tank which I used to do.
This pick is the only thing that makes me enjoy the game atm so I am open to trying many things so if you ever have more suggestions let me know :)

Sorry for not replying earlier, I am updating my build currently since i have improved at theory crafting over time. Hope you enjoy:)

I find triumph extremely useful on tanks or any champ in general, it increases survivability and allows you to snowball some more with the extra gold.