Question with Goyo and Colossal fighter

So here is the quesiton? If my opponent has a colosus out on his side of the field, and I summon from my hand Black Wing Gale the whirlwind, use his effect to cut colossal's atk in half, then I synchro to bring out Goyo guardian, and I atk and destroy Colossal, what happens? Do I get Colossal or does my opponent?

You would get it as turn player has priority for monster's effects.

Actually, that is right but because of a diff reason. Colossal's effect is not optional so it triggers 1st, then the player with Goyo targets Colossal, and the Colossal effect fizzles. The Colossal player should know he's going to lose his monster and should target a diff warrior. If, Goyo's effect did activate 1st it wouldn't be able to get colossal. Think about the Colossal vs Colossal matchup, thats y neither attacks because 2nd player's effect would end up resolving.