Mysterious Pyramid

When Mysterious Pyramid enters the battlefield,
Clash and Echo.
{t} Create a 4/1 Shapeshifter token with Banding, Plainswalk, Flanking, Phasing, Epic, Fear, Changeling, Horsemanship, and
Cumulative upkeep: 1 life.
{ut} Lose one life.
{t} Play a subgame of Magic against target player,
using your libraries as decks. The loser of the
subgame loses the game.