Elementary, My Dear Watson! 720.6
The fact that this planeswalker can be your commander opens up some pretty cool dragon-focused control builds
Inspect in the same order every time Start with identity, then structure, then cosmetics
UR Ultra Rare Nibiru, the Primal Being X LIGHT Level 11 [ RockEffect ] ATK 3000 DEF 600 During the Main Phase, if your opponent Normal or Special Summoned 5 or more monsters this turn (Quick Effect): You can Tribute as many face-up monsters on the field as possible, and if you do, Special Summon this card from your hand, then Special Summon 1 "Primal Being Token" (Rock/LIGHT/Level 11/ATK ?/DEF ?) to your opponent's field (this Token's ATK/DEF become the combined original ATK/DEF of the Tributed monsters)
They go for fifty bucks retail, and for hundreds of dollars on the secondary market, and can yield some seriously valuable cards
If each creature the defending player controls can't block for any reason (such as being tapped), then the target creature isn't blocked
