As a nine-mana Dragon, her Affinity for artifacts makes it trivial to cast her for as little as two red mana in a deck filled with mana rocks and Treasure tokens
Mississippi River utilizes Creative Technique and a bunch of cards with Cascade that cost six or more mana
With all of the Treasures, Food, Clues, Powerstones, Blood and token artifact dorks running around that's very doable, and drawing a card after scrying on a +1 on a four-drop 'walker is why she here on my first list
Spell or Trap cards with different names from your Graveyard to destroy all cards on the field
Power level wise the card fits in just right in Modern, as there are a lot of threats which go under the card, and cards like Veil of Summer and Cavern of Souls give slower creature/combo decks enough counterplay against it
There are roughly 100 assassins in the game as of the Assassins Creed Universes Beyond product