For example, player A plays a card, and so player B has the chance to activate their own effect
Players can also buy a Starter Kit, featuring starter decks for Cloud Strife and Sephiroth from Final Fantasy VII, bundles with 9 play boosters, and both Play and Collector booster boxes
Gather 3 monsters and Xyz Summon Number 102: Star Seraph Sentry and Number 32: Shark Drake to inflict massive damage
Latias EX (Special Illustration Rare) Latias EX from Surging Sparks boasts stunning artwork by OKACHEKE
That seems to be just for flavor, and summon doesn't have any impact on the rules that we know of
I do not have Pact of Negation in my cube presently however its value rapidly increases as the number of suitable archetypes for it increases and with cube design being as diverse as it is you can easily include more of those archetypes from one of a few different approaches