Nine great Celestials still ruled in the moment the gate was opened. Of these, four bought their war directly into our reality. Of those, Lucifer and Azrael were the most determined and destructive. They reduced galaxies to nothing but light and heat, but in time even they cooled and became contaminated by the material realm, and eventually found the reality that had forged them had become hostile to their very nature. Seeing their brethren fall, the others drew back beyond the gate, to fight their war at a distance with servants and devices.
True Celestials (aka Arch-Angels)
The Archangels remain in Heaven/Tartarus and from there plan their war on creation. As long as the Tartarus Gate remains intact they have access to the Universe as it is, and seek to return it to the Universe as it was. As their titles suggest each Archangel has a different approach to the war. Raphael seeks the destruction of territory and worlds. Michale favours direct conflict with the entities of the lower realms. Gabriel is highly strategic and sends legions against multiple targets. Samael prefers to recruit agents from the lower realms with promises of power or admittance to paradise. The final three are known to exist but are less invested in the War and as such little is known of them, it can't even be agreed as to what names they should be given.
Raphael (the Destroyer), Michael (the Soldier), Gabriel (the Strategist), Samael (the Seducer), and the final three archangels
Fallen (ex Arch-Angels)
Lucifer & Azrael
The two great celestials took their exile very differently. Lucifer, the Morning Star, and perhaps the most aggressive of his kind, embraced his semi-material nature wallowing in the sensations and emotions that came with a physical presence. He concluded that his fall was something the others had foreseen, and encouraged. By urging him to extend himself they had knowingly seeded his downfall, betraying him with the intent to size more of heaven for themselves. He rails against his material prison, even as he seeks to sabotage the Celestial efforts to destroy the new reality. From his perspective, the material is a necessary evil for without it, he too would now cease to be. Having said that, he is no friend of life and the living.
Azrael is often referred to by the living as the angel of death. To others as Nyx, the personification of darkness and quencher of the light, took an alternate route. Maintaining the unfettered reason of the Celestials she has accepted her place in this new realm, neither embracing or rejecting it. She still expects the destruction of this reality and prepares for that day, but makes no move to hasten it. Rather than release the energy within matter, she consumes it her sustain herself in this reality. Death comes to all things, each in its own time, and she plans to be the last awareness in this reality before it reverts to energy. She will at times harvest a living world to sustain herself, but the days of wanton destruction have passed.
Azazel (the Scapegoat)