The full text of these abilities are 'At the beginning of the upkeep of the player who has the initiative, that player ventures into Undercity,' 'Whenever one or more creatures a player controls deal combat damage to the player who has the initiative, the controller of those creatures takes the initiative,' and 'Whenever a player takes the initiative, that player ventures into Undercity.'" One is triggered on "venture into the dungeon," the other is triggered by combat damage and upkeep
This is also one of the most valuable cards from Lorcana in general
He adds: "I already spend a lot of time in Photoshop", so actually creating the cards was no hassle at all
Chandra, Flameshaper Chandra, Flameshaper may be costly, but has a rockin' +2 ability that adds a good chunk of mana to go along with card selection
Anything missing or that you liked
Detention Sphere has been a useful sideboard card in many Modern archetypes, but only some of those would rather have a creature than an enchantment