Counter Intelligence Players love putting counters on things so having a precon that just focuses on charge counters and proliferating them is incredible
If Im being honest, Id have to rank it as the second most-egregious card with actual Eminence (third if we count Oloro), but it feels better due to the noble goal of trying to make big, dumb beaters viable in the format
Starfield Shepherd Five mana for a 3/2 with flying isn't great, but two mana for a way to go search for an Esper Sentinel, Blood Artist, Mother of Runes, Stonecoil Serpent, or Walking Ballista is excellent
If you're like me, and you like using combos to win the game, another tool to check out is Commander Spellbook
Other Flashback Cards There are lots of flashback cards that don't fit into a specific paradigm
Jecht, Reluctant Guardian // Braska's Final Aeon (Extended Art) - Final Fantasy (Near Mint) You want to be informed when the price of Jecht, Reluctant Guardian // Braska's Final Aeon (Extended Art) - Final Fantasy (Near Mint) reaches a certain value