Gate Keepers 21(2002)

Gate Keepers 21 is an anime series set thirty-two years after an alien invasion has been repelled and the international defense organization A.E.G.I.S has dissolved. Only a handful of Gate Keepers—soldiers with supernatural abilities to manipulate dimensional gates—remain active. When Ayane Isuzu discovers that two formidable enemies, Machine General and Devil Count, have resurfaced, the surviving Gate Keepers must reunite to prevent Earth from falling under siege once more. The series blends sci-fi action with supernatural elements as this ragtag team confronts threats that thought they'd defeated decades ago, testing their aging skills and resolve against overwhelming odds.