Any cards to pick up? Also will Red/Blue ace be getting any support?

Hi! I just started and play with blue ace and Newgate and have a good amount of the cards for red blue ace was wondering since I may buy the rest if any of the new sets will be getting new cards that support him as I only want to buy what I need. Also I am really intrigued by Black Brook that is coming out and if there are any cards I should buy now to prepare for his deck. Thank you!

Also how do cards rotating out work? What will the new cutoff be?