Generally on Katarina anyone who can lock down champs for you is useful to you but that doesn't mean that you only want champs who are good at lock-down, Having a good team, or a team that everyone has some idea of what they're supposed to be doing can lead to you having a really good game, as katarina you probably go in and there will be games where you don't die at all, and games where you will go 5/10 but hey, that's how you learn. oh and my favorite combo on katarina is Q<(gunblade)<E<A<W<E<A<R. Basically throw a dagger and use gunblade at the same time, then E to them get off one free auto attack which will then trigger the electrocute, but also use w so that you have your next dagger on the ground thus you can choose to E onto the enemy champ or E away to a minion or ally to escape or E to the dagger which works too. And Yes you can do Q<E<W< to quickly drop 2 daggers in the same spot.