From 'Abdul'Aziz ibn 'Abdullah ibn Baz to our honorable brother, may Allah grant him success. Assalamu 'alaykum warahmatullah wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you!)
Concerning your question about the bearers of the 'Arsh (Allah's Throne) and 'Izra'il (Azrael, Angel of Death):
Q: After 'Izra'il takes the lives of all creatures and all angels, and also the lives of Jibril (Gabriel), Israfil and the eight bearers of the 'Arsh, how will it be borne? Also, what will happen after 'Izra'il takes his own life by the Commandment of Allah?
A: All praise be to Allah, the Lord of the worlds, and peace and blessings be upon the man whom Allah sent as a mercy for the worlds to convey the Message of Allah to them, and upon his family, and Companions.
Allah (Glorified be He) created the Throne, the heavens and the earth and holds them all by His Almighty Power. Allah stands in no need of bearers for the Throne or any others, for He (Glorified be He) says: Verily, Allâh grasps the heavens and the earth lest they should move away from their places He (Glorified be He) also says: And among His Signs is that the heaven and the earth stand by His Command.
As to 'Izra'il, Allah will cause him to die by His Almighty Power as He wills, just as He causes the death of any other of His Creation. In fact, 'Izra'il is not death; death is something else. 'Izra'il is an angel put in charge of death, as Allah (Glorified be He) says: Say: "The angel of death, who is set over you, will take your souls." If Allah wants to cause the death of the agent, He (Glorified be He) is capable of doing anything and is the One Who disposes the affairs as He wills.
May Allah guide us all to that which pleases Him! Assalamu 'alaykum warahmatullah wabarakatuh!