Considering that there are 3 other moderators on the game, it is very likely that the super moderators of the series did that. You should ask them directly.
There is a functionality change relating to this that we'll look to get implemented when we get the chance.
Something seems to be wrong with the Silent Hill 2 mod list also. One of the mods changed the title of a category and now (including myself as the main mod) have been removed from the mod list.
Edit: All mods have been readded
Another series mods getting removed from someone else editing game categories issue here. Game Mods can't save settings when they check the series mods power box. Is this going to be fixed automatically or not?
The bug causing the 'Series moderators have powers here' option from getting unset has been fixed.
Any games that were affected by this still have the option unset though, either a game super mod can simply turn the option on again or otherwise contact a full mod or admin who can also turn the option on again.