In the '90s, saw an episode of an anime (Robotech???) where the team encounter a young male child who can turn into an adult-sized cyborg-like destructive weapon (with great anime hair?). The female member of the team develops a maternal bond with the child, and urges him to give up this aspect of his personality. In the climax, honoring her wishes, the child willingly rides into battle in his childlike form, and falls tragically to the bad guys.
Any idea about the anime, episode, and character names? Thanks! (If not, please point me to appropriate resource/forum/site.)