The 5 V-Tamer Tags
Tag of Earth (Red) is guarded by Lord Triceramon
Tag of Sea (Blue) is guarded by Lord Marine
Tag of Spirit (Purple) is guarded by Lord Vamdemon
Tag of Metal (Grey true colour unknown) guarded by MetalGreymon + SkullSatamon)
Tag of Sky (No Pic) guarded by Juriemon, Megadramon + Deathmon
Rei's Pendant happens to be a Digimental that has the power to evolve both Arkadimon + Zero (it does get used for both)