Ninjutsu for everyone and anything! So, the condition is based off of Ninjutsu, but it's a Polymorph variant. Which is absolutely love.But because you're randomizing your own creature into something possibly better instead of transforming something of your opponent's into possibly a lowly sheep, it feels like a blue-red card rather than just monoblue. Polymorph was fine because blue does do things like transform the enemy into apes, frogs, diminutive sizes, or frog lizards.
This card is broken! Think of it as Oath of Druids that monoblue can play and gives the opponent almost no time to respond. It also replaces itself with the creature you bounce (if it is not a token, which it probably will be). As written, this card is a vintage card (Mana Drain seems good for this), which is fine. If you want it to be a commander card, I would just make it nontoken creature. In my moment of greed I would then also make it itself a creature. :)