Most of these effects are mono-white cards, with some exceptions
Special Summon it, also you cannot Special Summon monsters from the Extra Deck for the rest of this turn, except Xyz Monsters
This unique set has captivated the Pokmon community since its release in 2000 and remains a beloved collectible for fans around the world
Likewise, it could be that they have a spell/trap set in their spell/trap zone, so you can place a spell/trap in that same column on your side of the field, and now theres 2 cards in that column, letting you special summon a Mekk-Knight to it On top of being able to get out strong monsters this way multiple times per turn, they have multiple effects, some of which let you move the cards on the field so that you can summon to the same zone (because the columns had 2 or more cards in them) multiple times by letting you move the card you just summoned out of the way and put a new one there
When equipped, its essentially a Vizier of the Menagerie effect on an artifact
With all the dark energy you put into your deck, that can mean getting to the dark side of life