this deck uses the lightsworn engine to fuel xyz summoning through chaos plays. gagagabolt x2 are a card from redu called gagagarevenge:
target 1 gagaga monster in your graveyard; special summon that target in face-up attack position, and equip this card to that target. if the equipped monster is used for an xyz summon, and this card is sent to the graveyard as a result: face-up xyz monsters you currently control gain 300 atk. when this card leaves the field, destroy the equipped monster.
http: yugioh.wikia.com wiki gagagarevenge
once gagagamagician is milled or used to xyz summon and detached, this card reuses him. gagaga magician is the main xyz summoning engine making rank 3's, 4's, 6's, 7's, and 8's in this deck.