When Lightning finds her sister turning to a crystal for fulfilling her Focus, she too ends up becoming a l'Cie, kickstarting the game's core story
You'd definitely want a playset of Nykthos, Shrine to Nyx and some sort of payoff for the extra mana like Elesh Norn, Grand Cenobite, Walking Ballista, or whatever other bomb you prefer
One can make creatures effectively unblockable by supplying protection and altering colors, and opponents' removal can be made useless in the same way
It occupies a similar space that Emrakuls Evangel and Fresh Meat do, but it creates creatures that mirror the power and toughness of the creatures that die (as long as they die in separate instances)
These showcase cards can be found in Core Set 2021 Draft Boosters and Collector Boosters along with any product which has those packs contained within them
Hunter's Mark is a more familiar kind of card, but a potentially very effective one