If you want to be truly competetive on PC pvp, you have to learn MnKB. There's a reason PC FPS esports players don't use controllers. The speed and accuracy mouse movement allows is objectively superior to sticks, and so the ceiling of potential things you can achieve with practise is also multiple times higher. If you stick to a controller, you're handicapping yourself when you start going against MnKB folks who have already made that potential into a personal reality. You'll probably manage against folks under your own skill bracket, but you'll start losing against those in your own who you would've otherwise been even with using MnKB yourself after becoming proficient with it. Learning an input device from the begining is a painful process. Most likely weeks of dedicated practise and at the start you'll be losing more than winning, even fights you know you would've possibly won on a controller. But it's worth it in the long run if you want to perform optimally on PC platform. Of course if you enjoy a controller enviroment or don't want to be competetive on PC, sticking to what you like is the way to go.