How many times did the angels descend to fight alongside the Messenger, may Allah bless him and grant him peace, and do they descend to fight with believers in the present time?

The angels descended to fight in the battles of Badr and Uhud. The proof of their descent in Badr is the Almighty's saying: "When your Lord inspired to the angels, 'Indeed, I am with you, so strengthen those who have believed. I will cast terror into the hearts of those who disbelieved, so strike above the necks and strike every fingertip of them'" (Quran 8:12). And the proof of their descent in Uhud is what Muslim narrated from Sa'd ibn Abi Waqqas, who said: "On the day of Uhud, I saw two men in white garments to the right and left of the Messenger of Allah, peace and blessings be upon him, whom I had never seen before or after." These were Jibril and Mika'il. The apparent evidence suggests that the angels also fought in Hunayn and Al-Khandaq (the Trench). Al-Nawawi definitively stated that their fighting was not exclusive to the day of Badr. There are also narrations indicating their fighting alongside the Companions after the death of the Messenger of Allah, peace and blessings be upon him.