Desosai, Frontline Decimator

Haste, Trample, Deathtouch, Vigilance, Toxic 3, Ward {5}
When Desosai, Frontline Decimator enters, its controller loses X life.
During each player's attack phase, add a +1/0 to Desosai, Frontline Decimator for each X you paid to cast it.
For every 5 forests you control, conjure a copy of Desosai, Frontline Decimator onto the battlefield with an additional +3/0.
{t}: Add {g}{g}{g} and lose 3 life.
{10}{t}: Conjure ten copies of Desosai, Frontline Decimator onto the battlefield.