I know rage stacking is bannable but why? I it's probably because of the 2 tap stuff but you literally need rage 6 for demonic rage to work. Does this mean demonic rage in general is illegal?

I think so

Doesnt demonic rage replace rage 6? im pretty sure people added back on either rage 6 or 5

Is rage 3 called rage stacking ( cause mine is rage 3 and I see lots of ppl get banned with like rage 5)

Dem rage replaces Rage 6

Rege stacking is defined as having any level of Rage and any level of Demonic Rage on an item at the same time.