TPC took their sweet time announcing the gimmick in full, but our new mechanic for the Sword and Shield era has finally been revealed
Emrakul, the Aeons Torn isn't easy to get into play through mana, but spells like Summoning Trap, Through the Breach, and Sneak Attack can and have been used to cheat Emrakul into play for far fewer mana
Bant Midrange foundation 2 Deputy of Detention 4 Frilled Mystic 3 God-Eternal Oketra 4 Growth-Chamber Guardian 4 Hydroid Krasis 4 Incubation Druid 2 Knight of Autumn 4 Llanowar Elves 2 Shalai, Voice of Plenty 3 Teferi, Time Raveler 4 Vivien, Champion of the Wilds Esper Midrange Planeswalkers from War of the Spark have strengthened Esper Midrange, especially with the additions of Liliana, Dreadhorde General, Sorin, Vengeful Bloodlord, and Teferi, Time Raveler
You want to make sure that your high-value, rare cards keep their value, whether you look to sell or trade your cards in the future or want them insured
Its mechanics in the game are also very useful