These targets can be anything from Molten Primordial to Emrakul, the Aeons Torn, the best of the Eldrazi titans
Putting the deck together requires you to determine how your mana will be able to cast spells and summon creatures, so limiting yourself to two or three colours is a good place to start
And who knows, we might be getting more legends like Kastral, the Windcrested and less like Nadu, Winged Wisdom
Since you can make a copy at instant speed, you can ramp by copying a Sol Ring or an Arcane Signet to have enough mana for an instant spell that can counter an opponents spell or destruction spell targeting a creature
After this, all other opponents must each decide whether to discard a card or allow the player to place a Construct, Robot, or Vehicle card onto the battlefield from their hand