Xorvom, Eternal Dragonlord

Eminence - If Xorvom, Eternal Dragonlord is in
the command zone or on the battlefield.
Dragons you control have Trample,
Haste and Cascade.
Indestructible, Flying, Trample, Haste
Whenever a Dragon enters the battlefield.
you may pay {2}{g}{u}{r}, if you do copy that spell.