Ra, Halcyon End

Split Second
Flying, trample
Echo: Sacrifice three other creatures.
When Ra, Halcyon End enters the battlefield,
you may have your life total become 5. If you do,
its power and toughness are each equal to the
amount of life you lost this way. Otherwise, it
has base power and toughness 5/5.
Pay 5 life: Destroy target creature.