White Monolith

{t}: add {w}{w}{w} to your mana pool.
{g/w}{r/w}{w/b}{w/u}{p/w}{w}: Create a 10/10 plains creature token with: "{t}: add {w} to your mana pool."
{t}, pay X life: Add {w} to your mana pool half of X times rounded as you choose.
At the beginning of each upkeep, if you control twenty or more plains, you may pay {w}. If you do, gain 1 life and repeat this process.
Manaburn - Any white mana in your mana pool at the end of any phase deals that much damage to you.