Of course, like any TCG, there are deck-building rulesso no, you cant just throw in every card you love
Vanille, Cheerful l'Cie is a Uncommon, Legendary Creature - Human Cleric card from the Magic The Gathering set Universes Beyond - Final Fantasy (MTGSC-FIN-0392)
Thanks to a quirky Alchemy interaction, MTG Arena players can already conjure Magic: The Gathering FINAL FANTASY bombs
If I recall there are four, the Piracy first, Reconnaissance Mission with cycling, the Bident above that can be tapped with two mana on an opposing turn to force them to attack and then the recently printed Vehicle called The Indomitable
Then, any time a creature you control connects, you goad every creature that player controls
There are no limits on the amount of times you can activate Najeela, which means that, should she somehow assemble a team of creatures that can pay for her ability, you will be facing down infinite combat steps