It lets you draw and discard a card whenever one or more Knights attack, regardless of if Sidar is in the command zone or on the battlefield
You get a great deal of monster for your mana with the Geist
All three types of cards can be powerful, though the same rule applies as with your Pokmon: no more than four of the same card in your deck
We had a creature type that was a perfect fit for the environment, had proven popular with players, and had a history of being in green and black
If we want to do something different with our decks, just jamming the world's best enchantments along with some great support cards will make a deck that will work, but isn't much better than just doing an equation: good cards + more good cards = good deck
So, it was settled: we would try aligning C20 with Ikoria: Lair of Behemoths