Even Vader needs to carry keys. That's right folks, he has a TIE Fighter and he drives it... sometimes... So you know the Star Wars Darth Vader Keyholder works perfectly! He can just look for himself on his keyring and eliminate any of that fumbling around that so often happens. 

I know what you're thinking, Vader can use the force he doesn't need no stinking keys! And maybe that's true, but you need them!