Hello there,

As per Wiki:

• Tenet Envoy: Fires rockets that become laser-guided while aiming; auto-reloads 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 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 determined by the Progenitor Warframe, as per the table below:

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 Magnetic as an elemental. Yes! Magnetic! Let's face it... no one in their right mind will put mods into a weapon to make it Magnetic... and the free Magnetic sounds much more reasonable.

OK, let's see what we got here:

• Pinpoint accuracy.
• Heavy Caliber's accuracy penalty is minimal on this weapon, especially due to its ability to be guided manually.
• Rocket explode in an 8-meter radius after impacting a surface or enemy.
• Reloads 1 round per second while holstered.
• Explosion inflicts self-stagger.
• Explosion has linear damage falloff from 100% to 20% from central impact.
• Extremely low ammo capacity; requires just 3 reloads to fully deplete all ammo reserves.

So we got 8-meter radius, that's enough, especially since we got stagger danger, and we don't want to get staggered.
Very low ammo capacity, we need more, but here Arcane Primary Merciless came in (+100% ammo max).
Passive reload stacks with the Synth Mod Set, consider that while building sentinel with its weapon with Vigilante Mod Set.

Bane of Faction mod is flexible, change it according to the faction you are up against, or put [Wildfire].

Enjoy, THeMooN85