The armies which are in heaven (ta strateumata ta en tōi ouranōi). See Rev 12:7 for Michael and angels warring with the dragon, and also Mat 26:53 for the angels at Christ’s call, not to say Heb 1:6., Heb 1:14; Mat 13:41; and Rev 5:11.
Followed (ēkolouthei). Imperfect active and singular (strateumata, neuter plural) of akoloutheō, graphic picture of the celestial Warrior with his angelic hosts “upon white horses” (eph' hippois leukois) like the Leader and, like him “clothed in fine linen white and pure” (endedumenoi bussinon leukon katharon) like the Leader again (Rev 19:8). Note endedumenoi here as in Rev 1:13; Rev 15:6.