Two-Headed Giant has the distinction of already being a decent card for its cost, especially in a Limited setting
For example, if the opponent sacrifices a creature that they control but you own, it will end up in your graveyard
1993 Magic: The Gathering Alpha Time Walk The Most Powerful Extra Turn Spell: Take an extra turn has always been one of Magics strongest mechanics, and Time Walk remains the most efficient extra turn spell ever printed, restricted in Vintage and banned everywhere else
Worth being aware of how much you pack especially if you don't have a lifegain fatty to fall back on
It also has Eminence, which means that as long as its in the command zone or on the battlefield, itll make dragon spells you cast cost one less to cast
Four mana equals three cards making these the Harmonize or Concentrate of card draw