Vectus of the Underscale

Flying, Menace

If a nonlegendary creature would die, you may instead exile it with a scale counter on it.

Once during your turn, you may cast a card in exile with a scale counter on it by paying life equal to its mana value instead of paying its mana cost. That creature becomes a dragon in addition to its other types. Then you may put a +1/+1 counter on Vectus of the Underscale