We think we need to defend Lumineon to a degree. Sure, it is unremarkable in the main games but at least it is a powerful Pokemon in PMD2 in its own right. It is in one of the two lines that has Storm Drain, that makes the whole team immune to Water moves. Not only that, but for PMD standards, its movepool is unusual in a good way, sporting the solid Water Pulse, Ice Beam and U-Turn, the borderline broken Agility as an egg move, and some unorthodox stuff like Bounce (MAX power and accuracy in PMD, good roadblocker on the AI partner) and Silver Wind, which usually don't appear on Water mons (applied to a monster house, the chance is high that its stats will be raised, including the overpowered speed). Its only competition is Gastrodon, who does not have a useful secondary skill, a meh movepool for PMD standards and a godawful stat progression, which actually makes it easily replaced post main-story by Lumineon.