Aengus

Aengus, God of Youth of The Tuatha De Danaan.
First appeared in Season 2.
Aengus was at Fionn Corvin 's Halloween Party in 1985. There he met Rachel Berry, who went to Dublin to visit him.
Rachel and Fionn went to Dublin at the same time, where Aengus rejected Rachel, telling her she wasn't a nice person and had no soul. He later revealed he did this not to break her heart as he is forever young.