A mage? Tatsuya is gonna look blankly at his brother. "Okay, uh, I don't know who's who here." He's gonna look around to see if he feels any senses that pings to him as magic oriented. "Maybe descriptions could help...? Ugh...”

He looks at the plant above his brother, then at his hand. Perhaps he could use Apollo’s fire magic and burn that plant... but it’s attached to a doorway, and Tatsuya’s not interested in committing arson anytime soon. Besides, he’s not sure if that plant really is the source of Katsuya’s problem. “Does that plant look familiar to you, bro?”