Is it possible to have a torrented game separate from a legal one?

Hello!

I'm very new to torrenting, haven't done it on a regular basis until now. So I was wondering, if I have a separate client (if that's even possible) will it be unable to lake over to a legal copy? Someone I know allow me to use their Origin account, and while they don't have all expansions I don't want to spoil anything for them. The fact they are incredibly anti-piracy doesn't help, either...

I'm bad at explanation - if you want me to elaborate, just ask. I'm aware this isn't a normal question but I'm just wondering before I break anything

Thanks!

Yes, you can have a legit copy besides a pirated copy on 1 PC but you must keep them strictly separated.
When you use someone else's Origin account you can't harm the game for that other party.