It's cheating on our definition a little since it interacts with spells on the stack, but it's a mind control effect at heart
This ramps and fixes your mana pretty well, while also providing a body that can chump block
After a fateful prison break from the Illuminary during the events of Rise of the Floodborn, the sea witch takes her vengeance out on the heroes and their glimmers in what looks to be a much darker expansion compared to the adventurous Into the Inklands set earlier this year
Number SevenExert Influence Exert Influence might not exactly qualify as mono-blue, but I think it does
Either that, or he just makes a permanent and game ending Glorious Anthem
Alternatively, it can just be a solid buff to a deck running a lot of dinosaurs, and you can simply cast it for 1 additional mana, giving all your creatures an instant benefit