I personally recommend running versions of attractions that have the highest numbers lit up: this allows us to use dice rerolling cards Barbarian Class, Pixie Guide, and Wyll, Blade of Frontiers, which are the most mana-efficient dice-rerollers, but force you to take the higher number
"Five or more mana values among cards in your graveyard" means there are at least five mana values among those cards
It will be a major tentpole release that will be fully draftable and legal in the Standard format from Day 1
They don't feel like anything
Japan accounts for 44.3% of the total, followed by the US (24.5%), Taiwan (3.8%), Germany (3.7%), and South Korea (3.5%)
To end the combo, just target your original, non-Dualcaster Mage creature with a Twinflame copy