Thurid also gives all those creatures a bonus +1/+1, which is a pretty solid lord effect to have in the Command Zone
Then when it dies, flip to the land and then you can flip back for three or just tap for mana if needed
It was remade in suspend form for two mana in Resurgence of Belief and has many forms these days but all compare poorly to the original
If your deck happens to be playing Eternal Scourge, Misthollow Griffin, Torrent Elemental, or Squee, the Immortal, you might consider Altar of Bhaal if black is in your color identity
In fact we have enough cards that make and interact with Treasures now that you can build a whole EDH deck around them, and I can bet you that Xorn is going in every single one its currently the top red card from the set at 1600 EDH decks on EDHREC, and the third most popular card overall
A standard Magic card (2.5" x 3.5") is significantly smaller than both A5 and A6 paper sizes