The effect of “Millennium Scorpion” is a Trigger Effect. Each time it destroys a monster on your opponent’s side of the field and sends it to the Graveyard as a result of battle, it activates. This effect can be chained to. You can activate “Divine Wrath” against it.
If “Millennium Scorpion” attacks and destroys a Monster Token, the effect of “Millennium Scorpion” does not activate because a Monster Token isn’t sent to the Graveyard.
If “Millennium Scorpion” has an ATK boost from its effect, but is removed from play with “Interdimensional Matter Transporter”, or flipped face-down, the effect is reset and its ATK returns to normal.