However if they activate Droll after you have used Kaleido to send Sheep and Gold leo to add it back, you no longer have any way to access Wolf and therefore cannot continue to combo
We've seen this template done successfully with the tri-color cards in the Khans of Tarkir block, such as Soulfire Grand Master
The best element about this cycle is that they can fit into a whole host on existing and new strategies in Modern
They act as the catalyst, allowing you to flood the board with your combo pieces, setting the stage for explosive turns where multiple characters swing for massive damage, forcing your opponent to burn through their entire hand just to survive
But if there are some games you play a lot and the cards get shuffled, I think its worth it
In fact, Yugi used this ability in the anime to save himself from an attack from Obelisk the Tormentor , so its been put to good use