Majesty Pegasus, the Dracoslayer — Ruling

Regola generale

About being treated as a "Majespecter" card:
This is not treated as an effect.
This effect is a Quick Effect, which can be activated in the Hand.
You cannot activate it during the Damage Step.
Even if this card's effects are negated, it is still treated as a "Majespecter" card.

The『your opponent cannot target "Dracoslayer" monsters you control with card effects』effect is applied to the opposing player. (Your opponent cannot target face-up "Dracoslayer" monsters you control with card effects. This is not an effect that affects your opponent's monsters.)
This effect can be activated even if there are no "Dracoslayer" monsters in your Monster Zone.
This effect applies not only to face-up "Dracoslayer" monsters in your Monster Zone when this effect resolves, but also to any other face-up "Dracoslayer" monsters that will exist there at some later point.
The『cannot be destroyed by your opponent's card effects』effect is applied to face-up "Dracoslayer" monsters you control.

About this card's ② nd effect:
This effect is a Trigger Effect, which can be activated in the Monster Zone.
You can also activate it during the Damage Step.
When this effect resolves, you first add a Field Spell from your Deck to your hand. Strictly afterwards, you choose a card from your hand and discard it. (These are not treated as having happened simultaneously.)