Their 3- and 4-mana costs make them a great play into one another
In most cases (see below), if you wait until the combatdamage step or end of combat step, it will be after combat damage has been dealt, so the Ninja won't deal combat damage
MTG Arena and MTGO do get the MAR cards, but with altered in-universe names and art (rather than names and art from the Spider-Man IP)
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Black Market: Getting the mana is not optional
Hostile Negotiations is the one Im hot on right now though it can be a draw six for a deck that can take advantage of it
Mostly, we're looking for admitted mistakes in the art, weird choices made by the artists, or instances where the art doesn't totally represent the card