They appear as standard skeletal soldiers, adorned in simple armor. They are armed with standard spears, and carry a giant vertically-wide octagonal shield composed of solid Onyx depicting Zeus. They often appear in large numbers, and will use their spears and shields to attack Kratos via phalanx tactics.
Olympus Guardians are rather weak, but they cannot be harmed until after Kratos has shattered their onyx shields. The primary way to do this is by using the Nemean Cestus. Once their shields are completely shattered, Olympus Guardians appear and fight identically to Olympus Sentries, and can be killed just as easily.
Olympus Sentinels are essentially more powerful variations of the Olympus Guardians. They appear similar to Olympus Guardians with their spears and Onyx shields, and attack in an almost identical fashion. The only difference being that their overall strength is greater.
Like the Olympus Guardians, Kratos must first use the Nemean Cestus to shatter their shields. Once their shields have been removed, they appear and fight very similar to Olympus Legionnaires, and Kratos can use the same strategies to defeat them.