New Nexon interview about CrimsonWood(NotE3)

Or the fact that as a monster it doesn't have to follow the player weapon wielding at all >_> Grendel the very Old is even humanoid and he holds his staff in the other hand.

His stance is not indicative of a Mapler. NPCs (and monsters based on them) are not bound by the rules of Mapler physiology.

This monster, however, seems to have a Mapler at it's design core. That is to say, the elements of this monster could just as well be armor, weapons, skin, etc. that a Mapler could use on their own character. And if this were the case, the crossbow she is holding would need to be in the data as a gun or as a shield. That's all I'm saying.

I think the idea was to do a version of the forest from Ocarina of time.

Because the idea of a labyrinth-like forest was first seen in Ocarina of Time. Their ideas were definitely not influenced by World 5 of Super Mario World.