This deck is built around Xyz summoning, in fact you could say it is its focus.
Summon out Gagaga Magician and pick a level for him to downgrade himself or upgrade himself. You chose level 8 for Magician. Then special summon to your side of the field Gagaga Child since you have a a Gagaga monster out on your side of the field and upgrade Child’s level to 8. Activate 2 Gagaga Bolt normal spell cards and destroy 2 monsters on the field (1 each). Overlay the 2 monsters and Xyz summon Number 40: Gimmick Puppet of Strings and play the normal spell card Xyz Burst. Since you have Number 40, a rank 8 Xyz monster Xyz Burst destroys every set card your opponent controls.
The possibilities with this deck is endless if you have a full extra deck.