Target 1 Set Spell/Trap Card on the field; destroy it. During your Main Phase, except the turn this card was sent to the Graveyard: You can banish this card from your Graveyard, then target 1 face-up Spell/Trap Card on the field; destroy it. You can only use this effect of "Galaxy Cyclone" once per turn.
You can use Galaxy Cyclone on these cards when they were set by your opponent, in order to destroy them (it is still destroyed if they were to chain their activation to your Galaxy Cyclone). You can banish Galaxy Cyclone later on to destroy these cards if they activate other copies of it.
I can't say which one is good for sure. But the best backrow removal right now are cosmic cyclone and galaxy cyclone. Both have their pros and cons. If you have no cosmic, then you may as well get 2 galaxy. Think about their pros and cons and you can decide which one to get with dream ticket.
Situational. If you're running fast decks or using skills that require lp loss, then Cosmic Cyclone is better. If you're running slower decks, then Galaxy Cyclone would be better as it can remove or force backrow cards twice.
You can cosmic cyclone, then Cyber Style into tribute summon.
Finally got this card. Now with this, cosmic cyclone, and dust tornado, I feel like I got enough backrow removal cards. I thought about heading over to pvp for a few matches before the maintenance starts. But now I'll just wait until tomorrow when the nerfs happen.