Two generic, one black mana, Sacrifice Stalactite Stalker: Target creature gets -X/-X until end of turn, where X is Stalactite Stalkers power
Standard cards run about 0.30mm thick , which lines up with the 20pt24pt range used in the trading card industry (the pt here refers to thousandths of an inch, a holdover from printing terminology)
Mana Vault Mana Vault is part of a nasty 2-card combo: Mana Vault plus whatever busted 4- or 5-mana spell you want to play on turn 2 strong enough to be banned in Legacy and even restricted in Vintage
As such, if you have some powerful dice-rolling cards you want to get rid of, now may be the time to do it
Chromatic Orrery is also great because it can be tapped to cast Reaper King if there isnt any commander tax yet
Solemn Judgment and Vanitys Emptiness are at their strongest when going first, but are still decent when going second in this build