legendary souls isn't exactly a good way to measure your skill, as the computer seems to take predictive measures in that mode. and when a computer is predicting you, you're really screwed, no matter who you are. that mode is considered a joke due to how insane it is.
i'd say, play around online in player match. watch the other players while waiting for your turn, and when you see good players, find a way to play against them. if you don't have much trouble from them, then i'd say you're ready to at least attempt competetive play.