One mechanic thats very popular in Politics decks (and Commander in general) is monarch

Brago, King Eternal Ultimate Masters Guilds of Ravnica Niv Mizzet, Parun, Emmara, Soul of the Accord, Lazav, the Multifarious (decklist in the comments), Tajic, Legions Edge, Etrata, the Silencer, Izoni, Thousand-Eyed Commander 2018 Aminatou, the Fateshifter, Xantcha, Sleeper Agent, Lord Windgrace, Brudiclad, Telchor Engineer Core Set 2019 Sai, Master Thopterist, Goreclaw, Terror of Qal Sisma, Vaevictis Asmadi, the Dire, Chromium, the Mutable Battlebond Dominaria Teshar, Ancestors Apostle, Grand Warlord Radha, Arvad the Cursed, Muldrotha, the Grave Tide, Slimefoot, the Stowaway, Yargle, Glutton of Urborg, Squee, the Immortal, Firesong and Sunspeaker, Jodah, Archmage Eternal, Tiana, Ships Caretaker Masters 25 Rivals of Ixalan Azor, the Lawbringer, Etali, Primal Storm, Nezahal, Primal Tide, Zacama, Primal Calamity, Tetzimoc, Primal Death, Zetalpa, Primal Dawn, Ghalta, Primal Hunger Unstable Grusilda, Monster Masher, Dr
#16 Barreling Attack (Mirage) Why is it bad
But Shapeshifter can turn face-up as a copy of the Elemental for just 2 mana, which basically works like Time Walk in most situations
Impending is a textbook case of an alternative cost : You can pay the full cost and get the whole enchantment creature package right now, or pay a different (in this case cheaper price) for a different effect (just the enchantment, in this case)
Read More: The 10 Best Enchantments In Commander 7 Emry, Lurker of the Loch Emry, Lurker of the Loch is a three mana Blue 1/2