When I activate the second effect of <<14905>> that Special Summons <<4041>> and <<4766>>, my opponent chains the effect of <<6980>>. As a result, if my <<4041>> (or <<4766>>) is banished from my Graveyard, and there are no other copies in my hand or Deck, how does the effect of <<14905>> resolve?

DARK 6

Gains 300 ATK for every "Dark Magician" or "Magician of Black Chaos" in the GY.

DARK 7

''The ultimate wizard in terms of attack and defense.''

DARK 8

"Dark Magician" or "Dark Magician Girl" + 1 Spellcaster monster Once per turn, if a Spell/Trap Card or effect is activated (except during the Damage Step): You can draw 1 card, then if it was a Spell/Trap, you can Set it, and if it was a Trap or Quick-Play Spell, you can activate it this turn. If this card is destroyed: You can Special Summon both 1 "Dark Magician" and 1 "Dark Magician Girl" from your hand, Deck, and/or GY.

DARK 1

(Quick Effect): You can discard this card to the GY, then target 1 card in your opponent's GY; banish that target.