Dark Magician of Destruction — Ruling

Regola generale

About『Must be either Fusion Summoned, or Special Summoned (from your Extra Deck) by banishing 1 Level 6 or higher DARK Spellcaster monster you control during the turn a Spell Card or effect was activated』:
It's not treated as an effect. It's the method and procedure to Special Summon this monster in the Extra Deck.
Both Fusion Summoning and Special Summoning with the listed method are proper Special Summons of this card.
Generally these methods are the only way it can be Special Summoned. (Even if this card is sent to the Graveyard or banished face-up after being Special Summoned by one of these methods, it cannot be Special Summoned with other effects.)
It can be Special Summoned with the listed method in a turn that you or the opponent activated the effect of a Spell, and that activation wasn't negated.
A Chain Link isn't created when Special Summoning it with the listed method.
When Special Summoning it with the listed method, a Level 6 or higher DARK Spellcaster monster must be banished from your Monster Zone. (A face-down Defense Position monster can also be banished.)
When Special Summoning it with the listed method, banishing and Special Summoning don't happen at the same time.
Special Summoning with the listed method can only be performed during your Main Phase.

About this card's ① st effect:
It's an effect that isn't classified as an Ignition Effect, Trigger Effect, Quick Effect, or Continuous Effect.

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.
『1 card that mentions "Dark Magician"』refers to a monster that mentions the specific card name Dark Magician in its text.