Majestic Star Dragon — Ruling

Regola generale

This effect is a Quick Effect, which can be activated in the Monster Zone.
When your opponent activates a Spell/Trap Card, activates a Spell/Trap effect, or activates a monster effect, it can be activated by chaining directly to that effect.
It can be activated even if your opponent controls no cards.
Tributing this card is the cost to activate this effect.

During the turn you apply the effect 『Once per turn: You can target 1 face-up monster your opponent controls; negate its effects until the end of this turn』, one of the effects written in that monster's text can be activated as this card's effect.
The type of effect (Ignition, Trigger, Quick), activation requirements, whether or not it can be activated during the Damage Step, whether or not it has a cost, whether or not it targets, and any other conditions for activating the effect being activated by this card will be the same as the original effect.
Even if the effect of the negated monster is mandatory to activate when the conditions are met, whether or not this card activates that effect is still optional. Furthermore, when activating a mandatory effect as the effect of this card, the way the Chain is formed is still based on the original effect.