the white witch’s wearing of something made from aslan’s mane to battle was her way of boasting that she defeated him. aslan devoured her at the end of the battle.
Aslan: If the Witch knew the true meaning of sacrifice, she might have
interpreted the Deep Magic a little differently. For she would know
that if a willing victim who had committed no treachery died in a
traitor's stead, the Stone Table would crack and death itself would
begin to unwind.
the breaking of the stone table was like the tearing of the veil that separated people from the holy presence of God.
For Christ also died for sins once for all, the just for the unjust, so that He might bring us to God, having been put to death in the flesh, but made alive in the spirit. (1 Peter 3:18)