To be honest, I was getting a huge feeling of repetition with this show, and was going to stop watching it after episode 18. A few more comments on here made me watch the rest of the currently subbed episodes.
Episode 19 = filler. Bleh, skip! (Well until the ending, anyways.)
Episode 20 = They've pulled another timeskip. Whenever they do that in this series I think it always seems... bad. They can't pull off timeskips well (mainly because when they do, they either add a small amount of explanation or none at all.) And what was with Cal?! Seriously, 2 years and she looks like... THAT?! 0.0;;
Episode 21 = Getting better. Cal's remixed theme sort of bugs me a bit (not too much, though) and hey, a face off between Ein/Elen and Drei/Cal? I'm there! XD