Personally I really like the Spur series of swords (including the 3* Arc Razor and 4* Winmillion) and believe that a 5* sword in the series would be interesting for endgame content. I also think that other weapons and some of the various armor sets/pieces could be far more interesting (and would see far more use) if they were extended as a series. Other examples would be the Troika line and the Vitasuit, or even the low-level guns like the frost and stun guns, or the zapper, which are all essentially status inducing versions of the Blaster series that deal normal damage instead of elemental like the Alchemer series'. I'm curious as to what others opinions on the subject are, or even why the devs. chose not to extend certain gear to a full alchemy path, or at least to the point of being viable endgame equipment.

IGN: Grakn