The Gates are guarded by two creatures which become your greatest fears and horrors, then attack. What the two creature's are is unknown. Flying over the gate is impossible and so is going under, the only way through is either with permission from "Zero" himself or to beat the two creatures.
"Zero" will NPC as the creatures so once you set foot at the gate, please PM me your Fears and Horrors are and I'll pick what the creatures become, unless you have only one fear or horror then they become that just x2. I will be fair when playing as them.
