They dont go away as steps, phases, and turns end, and effects that add mana of any type to your mana pool cant give you energy counters
Rosewater is MTG's head designer, a position he's held since 2003
Put the rest on the bottom of your library in a random order. Thats a lot of text, but basically: if you play a card that costs seven mana, you get to look at the top seven cards of your deck, and then cast a spell from among those cards that costs seven mana or less for free
Enchantments that have a good spell-based effect when they ETB, like Omen of the Sea, Treacherous Blessing, or even The Kami War, are perfect to get the most out of your enchantment recursion cards
You can absolutely untap a land and then tap it again to obtain more mana
Peregrin Took Peregrin Took works well as a token commander because youll get extra benefits from each token you create