That can include The Queen, Commanding Presence herself, doubling her strength up to a mighty eight if you have the actions or effects able to ready her up to challenge on the same turn
Another recurring aspect of these dragoons is that they're often cloaked in mystery, information on them is hidden from the player
Modular was a cool effect from the original Mirrodin block, but Reyhan, Last of the Abzan goes beyond that
Additionally, this effect is highly situational, and not really worth using except in the situation where it allows you to win the game anyway, so I think we have to look at the Discover part almost as an alternate mode that you use when the creatures cant block part is irrelevant, which will be often It looks a lot like Goldvein Pick, a piece of equipment that really overperformed in Kaldheim
This includes Dimir cards, for example, but to meet the exile total you need to choose cards with a total of 15 black mana symbols
When there are characters on the field whose combined cost is 5 or higher, he can look at his top Life card and play it if it's a Supernova character