Tenet weapons are a special variant of existing Corpus weapons carried by a player's Sister and can be acquired once the Sister is Vanquished. If the player has enough weapon slots, they can claim these weapons from their Foundry, bypassing the supposed Mastery Rank requirement on these weapons. The weapons vary in attributes, dependent on the Sister the player has slain. The Energy Color on the weapon is depicted by what elemental bonus was augmented on the weapon during Sister creation and the progenitor Warframe. All weapons have an equal chance of spawning from a Sister.
Certain Tenet weapons are unique to Sisters, and are not based on existing Corpus weapons.
There are also unique melee Tenet weapons. These are not obtained from Sisters, instead they are bought from Ergo Glast in any Relay for 40 Corrupted Holokeys, and their availability is not affected by the player's reputation with The Perrin Sequence syndicate. The bonus element and bonus percentage of Ergo Glast's Tenet weapons cycle every 4 days.
A Tenet variant of a weapon will only provide mastery points once. A second weapon of the same variant but with a different Lich name will not provide extra mastery. These weapons have a max rank of 40. To obtain the maximum rank, the player must polarize the weapon five times, with each Forma increasing the maximum possible rank by 2 (similar to ).
The Tenet weapons additionally have bonus damage of one damage type, ranging from 25-60% of the weapon's base damage determined randomly, with lower percentages being more common. The damage type of this bonus damage is determined by the Progenitor Warframe, as per this table.
Note: This additional bonus damage applies as weapon base damage, meaning elemental mods and status that scale from base / modified base damage will be affected.
Valence Fusion combines two of the same Kuva or Tenet weapons into one with a higher Elemental Bonus. Valence Fusion can be found under the Actions button while modding a weapon. After selecting Valence Fusion, a player is required to choose another of the same Kuva Weapon from the inventory (not in Foundry or with the Kuva Lich) to fuse it with. If the weapon's element bonuses differs, the player will be prompted to choose between the two available elements. The elemental bonus caps at 60%. Any other properties (Orokin Catalyst, Forma, Stance Forma, Exilus Weapon Adapter, or Focus Lens) do not transfer over, meaning the order of fusion is important.
Example: (A) has 40% Damage and an Orokin Catalyst. Kuva Kohm (B) has 52% Damage. The player has two options, to fuse (A) with (B) or to fuse (B) with (A).
Since 52% is higher than 40%, the result will always be according to the percentage of (B) and multiplied by 1.1. So 52 x 1.1 = 57.2 , (57%)
After selecting the donor weapon to be used in the fusion, a confirmation screen displays the desired weapon's new damage type and bonus values and warns that the transfer will consume the selected donor weapon. Players are then prompted to type FUSE to confirm the fusion.
For Weapons and same-tier Armaments, fusions can be achieved at the following percentages:
|Minimum Initial Value||Maximum Number of Fusions|
- When sheathed, , , , and fold up into an attaché case.
- Non-Tenet variants of the and , wielded by Juno Crewmen, Juno Combas, and Zercas which are exclusive to those enemies and not obtainable for players.