Metatron

Metatron is the chief angel of Heaven and the strongest angel in all of Heaven.

Power
Metatron is the absolute strongest angel in heaven and leads a small group of the strongest angels in heaven that keep peace and order theough out the paradise known as the Arch-Angels, he casually goes by the name "Micheal" but to his enemies he is "Metatron, leader of Heaven."

Metatron vs Samael.
The first time these two confronted, was leading a charge for the then leader of Hell, Lucifer,towards the holy spire of God which held the seat of god's power, his throne, The Arch-Angels made quick work of hi brigade, Samael of course was not at the level he is now but still a formidle foe of Heavan, Metatron stood down his Arch-Angels and stated,"He is mine", soon after the two clashed blades, with Metatron losing and Samael nearly killing him, and destroying all of heaven, if it werent for the help of the Arch angels and all of heavens populace using all there power to seal him away, but with a cost,Metatron becoming to weak to defend heaven, a few thousand years later, Samael gathered enough power to dstroy the seals placed oh him and then became the current version of him, Metatron as the rest oh Heaven becoming weak and near mortal,to due the lack of heavenly power, only a few hundred angels still exist.