Factions

There are currently 4 major factions present in Warframe, three of which serve as enemy factions.

• The playable faction is the Tenno—descendants of warriors from the bygone Orokin era. Following an unspecified war, the surviving Tenno were cryogenically preserved for centuries before being awakened by The Lotus, a mysterious (though benevolent) figure who guides them during missions. The Tenno are extensively trained in the use of Warframes, suits that grant them various abilities for combat and support.
• The primary antagonistic faction is Grineer Empire, fascistic, militaristic brutes who dominate the solar system. Relying on mass cloning and cybernetic enhancement, they primarily use sheer numbers to overwhelm and overpower their foes,occasionally supporting their troops with specialized or heavily armed soldiers.
• The second major enemy faction is Corpus, a proto-corporation who control the trade routes across the solar system and reverse-engineer their technology from any Orokin artifacts or Warframes they find, viewing said artifacts as a resource exploited at any cost. As a result their soldiers—while frail compared to their Grineer counterparts—are equipped with advanced technology and are assisted by sophisticated mechanical drones.
• Infested is the last enemy faction. Being victims of the "Technocyte Plague"—largely unfortunate Grineer and Corpus soldiers—they have been warped into monstrous abominations. Much like the Grineer, they rely heavily on sheer numbers to overwhelm their targets but lack any significant ranged abilities. Occasionally scattered in the Infested swarms are Ancients, individuals in much more advanced stages of infection and endowed with unique abilities.[citation needed]
• While the Orokin are not directly encountered, missions that take place in Orokin derelicts are inhabited by "Corrupted" foes; raiders and trespassers (composed of soldiers from the previous factions) who have been brainwashed into protecting these derelicts at all costs.[citation needed] Occasionally players may be accosted by Stalker, a vengeful figure (strongly implied to be a rogue Tenno) who appears in response to a successful assassination for revenge, The Grustrag Three who appear in response to supporting Corpus in invasion missions, or the Harvester (also known as the Zanuka Hunter) who appears in response to supporting the Grineer in invasion missions. Defeating these enemies may reward the player with blueprints or parts of unique weapons.