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
The obvious home for this is with Wheel of Fortune effects, where every player discards their hand and draws 7 cards
If you are able to pick up the right pieces for the green-blue-black mill-yourself deck (which should be relatively easy to do if you see yourself getting passed late Mulches and Dream Twists), then you will be in a great position to go undefeated in your draft
Read More: Commander Challenge Dragon Throne of Tarkir Lolth, Spider Queen Lolth, Spider Queen may not be the most powerful of cards to come from Adventures in the Forgotten Realms, but its sure to be one of the most flavorful from the set
If people are curious, I can also do a dedicated comparison post showing light reflection, edge behavior, and thickness side-by-side Hope this helps :) Note: as an Amazon Associate, I earn from qualifying purchases
Tovolar gives you the most card for the least money if you dont mind two colors