Thunder Dragon Colossus X DARK Level 8 [ Thunder / FusionEffect ] ATK 2600 DEF 2400 "Thunder Dragon" + 1 Thunder monster Must be either Fusion Summoned, or Special Summoned during the turn a Thunder monster's effect was activated in the hand, by Tributing 1 Thunder Effect non-Fusion Monster (in which case you do not use "Polymerization")
It was banned in Modern for its sheer efficiency
The process varies depending on your specific needs, but the technical setup must be correct
There are only 1463 flash decks among all colors and leaders, so we'll take the biggest leader in that archetype out for a spin from a previous Commander set
Draft decks on the other hand have always been more focused, had lower mana curves and a better overall mana base, which allowed to lean to playing first more often
Its obviously most effective in an elf deck but can also do well in decks that run changelings or cards like Maskwood Nexus