Metagross. It secretly shitposts, but oftentimes lurks.
Garchomp, it posts as much anger as possible to vent away from getting bullied by his draconic brethren.
Heatran checks once in a while, but lurks all the time. When it does post shit, it's often a new thread.
Druddigon posts in the Showderp threads.
For the pokegirl threads, we have either Gengars trollin' along, or we have crazy shit like Roserade white knights and obsessive Sharpedos.
Blaziken posts in /fit/ more frequently than in /vp/. Swampert is now just lurking in /fit/ reading upon Blaziken's threads.
Reuniclus is a janitor.
Zygarde is a mod.
I know all these things because I'm actually a Xatu.