Your search for "Mistral Singer 58" revealed the following:
Mistral Singer (M21) from Core Set 2021, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Ryan Yee Card Text:FlyingProwess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Mistral Singer (Foil) (M21) from Core Set 2021, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Ryan Yee Card Text:FlyingProwess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)