How does this deck work?
Just search for
Urza's lands like every Tron deck, then search for
Molten-Tail Masticore.
You can discard
Elvish Spirit Guide for mana aceleration and to get creatures to
exile from Graveyard.
You can discard every other creature with the Masticores you have on battlefield.
With
Urza's lands pay 5 times
Molten-Tail Masticore second ability (and
exile 5 creatures) and you win.
The Changeling Shapeshifters are on the deck only to make it Tribal Wars (1/3 rounded up of the cards on the deck must be the same creature type).
If you wanna make it more competitive just take out the Shapeshifters and take some creatures you can discard for free (
Simian Spirit Guide,
Elvish Spirit Guide... etc.).