To activate the effect of Evilswarm Exciton Knight, the opponent must have more combined cards in their hand and on their board than the player activating the effect, but this is often trivial if players are using this effect when going second
I can't remember who made them or where I originally found them but any one can use them
We personally use the Vault X Exo-Tec ME 4 Edition Zip binder made specifically to organize your Chaos Rising Master Set
Its been years since I last played a game where neither me nor my opponent put a counter of any kind on the board, so the ubiquity of proliferate commanders makes them eternally playable, and more often than not, fairly powerful
This means that its better to sell these cards individually at the shop
The classic is Dark Depths and Thespian's Stage, but theres likely better options these days