When both of these cards are on the field together, Need for Speed is effectively a free damage engine
Japanese cards, promotional cards, and tournament cards can also be extremely valuable
The big question I've been getting on this card is "Isn't the ability white and not blue?" In general, yes, preemptive countering has traditionally been more of a white thing, but blueas king of the counterspellsdoes essentially cover similar territory
Let me break it down: When Lagrella, the Magpie enters, you can exile a creature each player controls (yourself included)
Adding all of these factors together, it seems like you can expect about 3 mana of value from the dungeon or a little less than 1 mana per room
I hope to see you all signing up for the tournament and flowing into the IRC channels