If you don't keep careful track of how your triggers line up, you can end up casting a spell for free you shouldn't cast - in the above example in a casual game, it would be very easy to think the Battlesphere could be cast because you forgot who's Cascade trigger it was
Pokemon UK website or TCGPlayer's rotation tracker
It can help a very tall Ygra, Eater of All, Rapacious Guest, or Ravenous Squirrel trample over blockers, its another artifact and enchantment sweeper, and it provides a lot of card draw in the right circumstance
The natural inclusions in any deck playing Darcy are Mishras Bauble, Unholy Heath and, if paired with Blue, Expressive Iteration and Counterspells
Then he can tap for three mana to make a 1/1 Elf and Warrior token