Completed Co-Op!

Woo!, alright, my friend and I finally beat our Swap Force playthrough! I gotta say even though the mother of Kaos wasn't as relevent as I had hoped, the game was amazing. I love the fact that they have character bios right there in the game, and the level design was superb! Now all we need to do is indulge in a few arenas and have fun with PvP.
Side note: I have already obtained a few figures for a Giants Co-Op ( today in fact ). I have no Giants themselves yet, but I will probably order Thumpback via Amazon. Anyhow, I have a Series 2 Hex , and Cynder waiting on the back burner for now. My friend just ordered a Pumpkin Eyebrawl, and a Polar Whirlwind today but was really lucky to find a used Series 2 Bash, and so he got Sprocket, and Series 2 Trigger Happy, and thanks to the buy 2 get 3 free he gifted me Hex, and Cynder! One that I really want to try is Chill. Any suggestion of Giants cores I should keep an eye out for?
Side note: I have already obtained a few figures for a Giants Co-Op ( today in fact ). I have no Giants themselves yet, but I will probably order Thumpback via Amazon. Anyhow, I have a Series 2 Hex , and Cynder waiting on the back burner for now. My friend just ordered a Pumpkin Eyebrawl, and a Polar Whirlwind today but was really lucky to find a used Series 2 Bash, and so he got Sprocket, and Series 2 Trigger Happy, and thanks to the buy 2 get 3 free he gifted me Hex, and Cynder! One that I really want to try is Chill. Any suggestion of Giants cores I should keep an eye out for?