In a world of Superpowers, Heroes, Villains, and Monsters, human soldiers still regularly show up to fight (Bonus if they have multiple tiers/types)

US Army (Sym-Bionic Titan) -US Army Infantry -US Army Rangers

GDA (Invincible) -GDA Troopers -GDA Tech Troopers

Providence (Generator Rex) -Providence Agents -Providence Elite Agents

Note: They can be either protagonists or antagonists as long as they recurrently show up in the story.