Time waits for no man.
Siegfried is known as a close associate of the late Albert Einstein. Though Einstein believed his technology should primarily be used for peaceful purposes, Siegfried has set out into the field to show that it is essential to weaponize Einstein's technology in order to protect the free world.
On the battlefield, Siegfried is the man that pilots the Zeitgeist, a massive craft that wields some of the Alliance's most advanced chrono-technology. He can bombard enemies from a great distance with a cutting edge weapon that creates a small, unstable chrono vortex, inflicting a huge amount of damage to anyone caught up in it.
When ordered to deploy, Siegfried creates a large, stable chrono-field, that temporarily phases himself and all friendly units in the area, out of this plane of existence, becoming completely impervious to most outside influence. However, phasing out makes any movement impossible. Due to the bulkiness and weight of his craft, Siegfried can't fit into most smaller transports and cannot cross water. However, he can still make use of Allied air transports.
Commander, if we are outnumbered, I can stall some more units around me, with the chrono bubble. But make sure you send more reinforcements quickly!
—Siegfried discusses his chrono freeze ability in Zero Signal
Siegfried is an effective siege hero capable of dealing long range bombardment to his enemies. His weapon fires a powerful, unstable chrono vortex that deals area damage and is highly effective against densely-packed enemy groups or structures.
Furthermore, Siegfried can deploy to create a chrono-field. This field makes himself and surrounding allies temporarily invulnerable to any type of damage, however unable to act and move.
However, Siegfried moves fairly slow due to the bulkiness of his weapon. He cannot be loaded into an Archon AMC and cannot operate its weapon from inside transports. Despite its floating Zeitgeist craft, Siegfried cannot travel across water. Besides that, Siegfried's weapon has a slow firing rate and is unable to fire at any air units. While he is immune to Attack Dogs and Spooks, Terror Drones are particularly threatening to his survival (especially if he is not escorted) as they are fast enough to evade his Zeitgeist Cannon easily.
There's no way we can let these Russians have the Professor's secrets!
—Siegfried during Operation: Panic Cycle
- In Zero Signal, Siegfried is introduced alongside the rest of the Euro Alliance to retake the Radar Domes and neutralise the Soviet Tactical Nuke Silo. He can die without compromising the mission.
- At the start of Panic Cycle, Siegfried accompanies the Battle Tortoise carrying KI Scientists and the MCV and leads a small task force to escort them to the SteinsTech Laboratory. If he falls down throughout the mission, he will reappear next to the SteinsTech Laboratory, but will no longer be controlled by the player. He is one of the very few survivors when the MIDAS hits.
- Siegfried, utilizing his personal Chrono Legionnaire suit instead of the Zeitgeist craft, rescues Tanya from Soviet captivity in The Mermaid. He starts at elite rank and has to survive throughout the mission.
- In Stormbringer, Siegfried and Norio help protect a Weather Control Device and later help clearing the Virgin Islands of PsiCorps presence. Both heroes can die without compromising the mission.
- In the Covert Ops mission Gridlock, shortly after the MCVs deploy Siegfried will arrive via chronoshift to aid Allied forces. Both heroes can die without compromising the mission.
- At the beginning of Insomnia, Siegfried and his initial group will clear the beachhead with the aid of the Paradox Engine's Time Freeze. He's the first of the three Allied heroes to arrive. If he dies, he'll be transported to the Paradox Engine to recover, then respawn after a few minutes.
- At the beginning of Unthinkable, Siegfried is among the Allied vanguard sent to destroy the PsiCorps base lying between the Allies and their target. He only appears at the start and is not actually encountered as an enemy unit in this mission.
- In Rainmaker, Siegfried is present among the enemy Euro Alliance forces. He's meant to be avoided by the player (who only has PsiCorps Troopers, light infantry and vehicles) and will leave battlefield along the road later.
- In Blut Royale, Siegfried accompanies Tanya and several brave Allied forces to defend the SteinsTech Academy from the invading Russian and Chinese forces. Both heroes can die without compromising the mission.
- Siegfried's design is visually based off the unused Red Alert 2 concept art for the Chrono-Legion turret.
- Siegfried is possibly named after a legendary hero of Germanic mythology, who killed a dragon and was later murdered.