Winged Dragon of Ra

As additional cost to cast this spell, sacrifice three creatures.
This spell can't be countered.
Flying, haste, shroud.
When this card enters in the battlefield, you lose
life until you only have 1, this card have +1/+1
for every life paid this way.
If Winged Dragon of Ra enters the battlefield
from somewhere other than its owner's hand, sacrifice it at the beginning the end step.