Detonate Deleter — Ruling

Effetto 1

This card's effect that destroys an opponent's battling monster at the start of the Damage Step is a Trigger Effect. (It does not target.)
This effect can be activated optionally at the start of the Damage Step when this card battles a face-up monster. (The effect cannot be activated if your opponent's battling monster is a Link 3 or higher monster.)
This effect can be activated not only when this card attacks an opponent's monster, but also when an opponent's monster attacks this card.

This card's second effect that destroys an opponent's monster is an Ignition Effect. (It targets 1 monster in your opponent's Monster Zone.)
Tributing a monster this card points to is the cost to activate this effect.