13AM Games has been sending out cryptic tweets for the last week or so, teasing content for Runbow in April. If you look at the tweets, you see a pattern with random letters being capitalized. When you put together all the capital letters, you get the following message.
Satura is the villain character in Runbow. Looks like she's ready for some new content all her own. We'll just have to keep tabs on the official Twitter account to get more details!