After hearing about Earth from Queen Beryl (who was later destroyed), Alan and Ann headed over there to take it over and drain energy from people for the Doom Tree, who needs energy to survive, and if it dies, they die. While posing as a human at Serena's school, Alan fell in love with Serena, and later discovered that Ann was in love with Darien, which made him jealous. Alan and Ann would send Cardians to try and extract energy, Alan usually being the one to awaken them by playing a song on his flute.
Eventually, the Sailor Scouts discovered Alan and Ann's true identities, and they fought them in the Doom Tree's room, but soon realized that what they were doing was wrong, and could tell the true power of love from Darien and Serena. Eventually the Doom Tree attacked Alan and tried to stab him with its branches, but Ann jumped in front of him to protect him and took the hit. The Doom Tree tried to kill Alan, too, but Sailor Moon stopped it, and it told them all that it needed love energy to survive, not negative energy. After being healed by Sailor Moon, it revived Ann, and Alan and Ann left Earth with the Doom Tree to start a better life somewhere.
Alan attacks by using an attack similar to a Force push from Star Wars. His human disguise looks similar to Jedite.
- Alan and Ann's names are a play on the word "alien".
- Alan's claim of knowing Queen Beryl was exclusive to the DiC Entertainment dub. In the Japanese version and Viz Media dub, the former made no mention of the latter, nor was there any indication that they ever knew or encountered one another.