The game (actually this card) is bugged. I've been meaning to run a meta deck with Gearfried and Destruction Swordmaster, but right now, Fried's effect cannot be triggered while an enemy monster is equipped to Buster Blader. I know it works bcs I tested it on YGOpro. How the hell hasn't this been noticed? This shouldn't be a bug.
By the way, I already reported this earlier today, but man... God knows when Konami sees to this bug. Luckily, the duel links support team is actually quick to solve issues.
Hey, I just thought I would test his effect with a legit EQUIP SPELL against my own block attack, and it still didn't work.
I think devs intentionally made it so that Gearfried can't negate YOUR OWN cards (possibly because it could cause confusion for beginners. or maybe for UI issues.)
So anyway, the card is still bugged, but it should work in PVP.