Tenno

"The Tenno are descendants of an ancient and mystical civilization of lost warriors from the Orokin era on Earth. Preserved in cryopods for centuries, the Tenno now awaken to a new war, fighting and resisting warring factions as the sole bearers of the Orokin-created Warframes.  While the memories of the Tenno have faded over time, their mastery of guns, blades, and Warframe exo-armor has not. Fragments of history suggest that discipline and chivalry are the cornerstone values of the Tenno: is this true today? The Tenno are emerging into a world unfamiliar to them. One sees a noble warrior, building his strength against an oppressive regime. Another sees an opportunistic mercenary, exploiting the Warframe's superiority for wealth. Regardless of their future, the Tenno stand united against a common foe, loyal only to each other."

- Warframe Official Website

"The Sentients had won. They had turned our weapons, our technology, against us. The more advanced we became, the greater our losses.  The war was over unless we found a new way.  In our desperation we turned to the Void.  The blinding night, the hellspace where our science and reason failed.

We took the twisted few that had returned from that place. We built a frame around them, a conduit of their affliction. Gave them the weapons of the old ways. Gun and blade. A new warrior, a new code was born. These rejects, these Tenno, became our saviors. Warrior-Gods cast in steel and fury striking our enemies in a way they could never comprehend.

Excalibur was the first."

- Orokin 'Warframe' Archives (Excalibur Codex Entry)

The Tenno are the faction controlled by the players. Each player is a Tenno with a suit of armor called a Warframe. The combat abilities provided by Warframes are vastly superior to both the Corpus' high technology and the Grineer's vast numbers; even the most inexperienced Tenno can fight their way through hordes of basic foot soldiers alone, and teams of experienced Tenno can best even the deadliest enemy threats.

Awakening from deep slumber to a hostile world, the Tenno know little of themselves.

Each Tenno bears a primary weapon, a sidearm, and a melee weapon. Their arsenal includes rifles of various types, shotguns, pistols, swords, and exotic melee weapons such as staves, axes, and power gauntlets. Different Warframes offer their own unique powers, ranging from Volt's burst of superhuman agility, to Frost's deadly avalanche. Also, Warframe armor's modular nature allows for major upgrades and wide customization options. Utilizing the arms, armor, and powers at their disposal Tenno squads have adapted to wildly different situations using only a moment of downtime between missions.

Weaponry


The Tenno have created a huge amount of "home grown" weaponry and equipment - much of it descended from Orokin counterparts, but some of it original. Tenno weapons in general tend to feature smooth lines, symbolic design, and an "organic" shaping that gives them a sleek, predatory look. Tenno weapons are actually among the most commonly available to players.

Lotus


Upon revival from cryostasis, the Tenno is guided by a figure known as the Lotus. Asserting preservation of her people by any means necessary, the Lotus dispatches and guides Tenno through missions of espionage, sabotage, defense, extermination, interception and rescue. On these missions, the Lotus guides Tenno using audio commands transmitted from an unknown location. Like the rest of Tenno culture, she remains shrouded in mystery.

Some weapons bear the Lotus emblem to distinguish them as being unique or Tenno-altered, while other weapons bear the symbol simply as a trademark of Tenno construction. Hostages liberated during Rescue missions appear to be human, and wear jumpsuits that bear the Lotus emblem. It is suspected that these hostages are human, or are unarmored Tenno.

Liset
The Liset is an agile unmanned Tenno dropship that is used to transport players to their missions and from extraction. Underneath the Liset is a single Vitruvian Man-like passenger compartment that opens when deployment or extraction is needed. The Lisets are also equipped with tractor beam technology that can be used to transport heavy cargo such as Formorian Power Cores.

General
The Tenno are mysterious in the extreme, with most details about their lives, origins, and motives unknown. Given this mystery, there is much speculation surrounding many aspects of the Tenno.

Considering that the Tenno can be kept in biostasis, require life support, can bleed, breathe, die, and that various NPCs, such as General Sargas Ruk and Lech Kril, refer to the Warframes themselves as suits, it is well established that Warframes are suits of armor, and that they contain living, organic Tenno. Lotus' in-game comment, "Other than you, I can't detect any lifeforms on the ship", which may be heard during extermination missions after all enemies are killed.

The Codex info from Excalibur Prime directly states that Tenno are individuals "twisted by the void", and that the Orokin built suits around them; those suits being prime Warframes. It is still yet to be explained how the Tenno ended up with industrially reverse-engineered Warframes, as opposed to the supposed Orokin variants.

At one point during Vor's Prize, Captain Vor says, "Tenno do not control the Warframe's divine energy. The Tenno are that energy. Each Warframe you control is merely a glass shaping your furious light." This seems to suggest that the powers each Tenno possesses come from the Tenno themselves, rather than their Warframes, and the Warframes may simply channel or enhance those abilities. This is further corroborated by the Rhino Prime Codex which describes an out-of-suit Tenno using abilities like Iron Skin without a Warframe.

In contrast to this, however, is the Infested Mesa encountered during Patient Zero which uses Warframe abilities despite being described by Lotus as "hollow" and without a Tenno. The same could be said for the presumably-Sentient-controlled Chroma in The New Strange, which uses its abilities as well - though the exact state of this Warframe is never directly elaborated on. There is also no hard evidence that the humanoid creature described in the Rhino Prime Codex is a Tenno, and the fact that the narrator was unaware of even the Zariman's return from the Void, though had worked on "countless" like the creature itself, may in fact disprove the theory altogether.

It can be assumed that the Warframes that existed during the war with the Sentients were unique - that is, that there were only single copies of each, built around a single Tenno. This is supported by the description of the Valkyr Warframe: the "original" having been experimented upon, and all subsequent Warframes being copies of that one original; thus reflecting the damage inflicted upon it. Furthermore, the Nova Warframe which was designed by the Tenno Council (as Lotus claims), the Mirage Warframe being lost "forever" upon her destruction (as revealed during the Hidden Message quest) and the parts of Limbo Warframe found all over the system after his destruction as revealed at the end of the The Limbo Theorem quest, plus the subsequent rebuilding of the frame from blueprints suggests that aside from a few basic Warframes, all were specially designed and singular - only copied en masse by contemporary Tenno fighting against the overwhelming numbers the opposing factions possess.

Trivia

 * The plural of Tenno is just Tenno.
 * Each Tenno behind the Warframes have official concepts and ideas to what they look like as stated by Art Director Mynki in Devstream #4 which may or may not be revealed in the future. These concepts may also be subject to change throughout development.
 * The Corpus seem to refer to the Tenno as "The Betrayers."
 * The moniker "Betrayers" seems to be partially explained by the Stalker's Codex entry, in which he claims that the Tenno slaughtered their masters at the Mercury Terminus in the aftermath of the Great War.
 * This is further explained by the Anti Moa Synthessis, which reveals the Corpus original from within Orokin society and became little more than scavengers after its downfall, explaining why they - and not just Stalker - see the Tenno as betrayers.
 * Possible note of worth, the Stalker refers to himself, and the others gathered around him as 'low guardians', making distinction between the low guardians and the Tenno. It is possible that the Tenno were regarded as 'high', or the highest, guardians of the Orokin. From the in-game description of the Misa Syandana Prime, we also know that there were Temple Guards as well.
 * Tenno (天皇) means in Japanese "Divine Emperor". Additionally, in the Buddhist faith, the Four Heavenly Kings (四天王,  Shitennō)  are four guardian deities who watch over each cardinal direction.
 * In the Profit trailer, Alad V insulted the Tenno as "mute peasants" for humor, referring to the fact that Tenno have never been heard speaking verbally.
 * Nova's Profile describes her existence as the result of "Tenno High Council" research, indicating that there is some sort of Tenno governing structure.
 * The "Tenno High Council" is a reference to the Design Council, a select group of players mostly consisting of Founders that can vote and provide opinions on concepts and designs made by Digital Extremes before they are released to the public. Nova was the first Warframe created from the Design Council's input.
 * In the prologue added in the recent update 14, Vor states that the Ascaris is nearly attached to the Tenno's spine. This implies that Tenno are biological and possess at least some biological structures that are analogous to those present in humans.
 * Previously, there was much debate about whether the "player character" was a single Tenno switching frames or multiple Tenno, each with their own personal frame (ala an MMO character select screen, all individual but all technically existing at the same time). Since the release of The Limbo Theorem and Ordis asking the Operator (the player character) to exercise caution when they "occupy this frame" is can firmly be said that the player is a single Tenno, and that they are indeed switching Warframes.
 * Shortly after this reveal there was some debate about whether or not Ordis was breaking the fourth wall, but in a Reddit AMA Steve confirmed it was not.undefined
 * The name "Tenno" dates back to the Hayden Tenno character from Digital Extremes's previous game Dark Sector. Warframe often uses concepts, art styles, names, and other materials from Dark Sector, due to it being a spiritual successor to the game itself. It has been stated by [DE]Megan that "Dark Sector and Warframe are inextricably linked."