Especially in Tweets, brevity is key. "Watch me take you over" feels clumsy to me. Maybe more like "Watch me conquer you?"  Or a completely different approach, make the threat sound positive: You will enjoy serving me.

Still working on the backstory (and catchprase), but I have relaunched Edgaaar with a clearer purpose, thanks everyone!  He now lives with a host family, where Jay will be the primary human sharing his adventures.  He tries to blend in as an alien just learning about the planet, but very clumsily always reveals his true purpose even though he really enjoys social media.  If anyone is interested, he is on Twitter and Instagram @edgaaarhorrible and FaceBook at /edgaaarhorrible.  His first video blog, which I am currently working on, will be a book review of Felicia Day's "You're Never Weird on the Internet (Almost)".  This video is where he sets up his #NeverWeird Bucket List.  Among things like rocking out at a concert and attending a comic con are the final items of creating an army and conquering Earth.  A future episode will introduce two races of the 4 systems he rules over, the Mu-kcos (Mew-Cuz) and the Cyfur.  LOL, simple names for a sock puppet and a one eyed furry sock puppet.  

I'm sure you have it in the bag now, but how about following the Trekkie Monster twitter account? They have a good example of streamlining tweets to be very specific about things.

I am a Tick fan,dumbest catch phrase ever "SPOON!"  Gotta love him, and those bad guys, they just kill me.  Watch a few old Tick episodes and your brain will be dumbified.