The Vast

Patron - The Vast can be your commander.
If it is, you may only cast it if the X in its
converted mana cost is 10 or more.
The Vast enters the battlefield with X charge
counters on it. When it does, create an X/X
Titan creature with trample and reach.
At your upkeep, create an X/X Titan creature
with trample and reach.