As for Clarion Ultimatum, the sorcery can do some really powerful things, but we also had a lot of games where it rotted in our hand while we tried to find the mana to cast it, and also a few where we had the mana but didn't really have any good targets (casting a seven-mana card and getting a Birds of Paradise, a Noble Hierarch, and three lands for our trouble doesn't feel all that good)
Play Megrim next as well as one of your draw/discard creatures such as the Cephalid Broker or Lore Broker or your force discard/draw creatures such as Barbed Shocker or Abyssal Specter (there are many other Specter creatures that will work as well)
This hack is a relatively straightforward, no-nonsense one that isnt the most inventive or imaginative mod we could find but it adds all of the extra levels and items that non-Japanese players would never have been able to access otherwise
Also, during this phase, a player may choose to play a card from his or her hand by tapping lands to produce mana
a resolved Consecrated Sphinx is still incredible, but its just not the tilt-inducing powerhouse it was in the early years of Commander