Hello there,

As per Wiki:

• Tenet Livia: Two-handed nikana that builds blocking angle from blocking; pauses combo duration when holstered.
• The weapon's max rank caps at 40 after 5 polarizations - max rank increases by 2 per Forma added (similarly as the Paracesis).
• All Tenet melee weapons deal innate elemental damage in addition to physical damage. The amount of this damage is random, ranging from 25-60%, while the type of element is randomly generated in Ergo Glast's shop, which are cycled every 4 days. Can be bought from Ergo Glast of The Perrin Sequence in any Relay for 40 Corrupted Holokeys.

According to the above, I added exactly 5 forma to this weapon, so we can obtain Mastery Points from it.

In this case, I recommend picking Cold/Toxin as an elemental. Depending on the chosen elemental, you will then use an R0 Cold/Toxin 60/60 mod.

Some info about melee:

• This weapon primarily deals Slash.
• Fast attack speed.
• Blocking enemy attacks increases the weapon's blocking angle.
• Holstering pauses combo duration.
• Below average range when compared to other double-handed nikanas.
• While sheathed, the weapon folds up into an attaché case.
• Combo resets when used with certain Warframe abilities and Exalted Weapons.
• Combo duration is reset when the [Tenet Livia] is used alongside the following Warframe abilities:

So thanks to above info, this melee isnot suitable for the so-called StatStick.

Anyway, the melee itself is kinda good, but definitely not meta. Very good Slash damage, so Viral is the obvious choice.
Very high Critical Chance and Status Chance, high Critical Multiplier, fast Attack Speed makes this melee a very reasonable weapon to pick.

Enjoy, THeMooN85