Red Duston

The monster effect "This card cannot be Tributed" is a Continuous Effect.

"Cannot be used as material for a Fusion, Synchro, or Xyz Summon" is not treated as a monster effect. (You cannot use "Red Duston" as material even if it is in your hand or Graveyard, or if it is in face-down Defense Position.)

The monster effect "When this card on the field is destroyed, its controller takes 500 damage" is a Trigger Effect. (It does not target. The player who controls the "Red Duston" at the time it is destroyed on the field takes the damage. It also activates during the Damage Step.)

The monster effect "You can only control 1 face-up 'Red Duston'" is an effect that is not classified as an Ignition Effect, Trigger Effect, Quick Effect, or Continuous Effect.