The Favorite Evolutions
Evolution I : Incarnon Mode
Hitting weak points charges Incarnon transmutation; alternate firing transmutes. Switching back will consume any remaining charge.
Evolution II : Rapid Wrath
+25% Fire Rate ( greatly improves the firing speed of normal and incarnon mode )
Evolution III : Rapid Reinforcement
+30% Reload Speed ( helps you reload faster for normal mode, which allows you to apply status effects faster )
Evolution IV : Lethal Lance
On Kill: +2.5 Punch Through for 20s . ( you hit many more enemies with each shot ) 🔥
Evolution V : Devastation Cascade
Hitting enemies in Incarnon Form increases the Critical Chance and Critical Damage of the fully charged blast by +5%. Stacks up to 50.

Headshots charge the Incarnon form. Alternate fire transforms the weapon into the Incarnon form of an arm cannon.
Brief Opinion of Build
In my opinion, I don’t consider the [Onos] to be a strong secondary weapon, so it’s best used in its Incarnon mode, as it makes the most of its potential with a critical damage of over 17,000,000, which is brutal and even better if you reload to the max and get a headshot in Incarnon mode. To sum up, these are the mod bonuses:
In my opinion, I don't consider the [Onos] a strong secondary weapon, so it's best used in its Incarnon mode, as it fully utilizes its potential with a critical damage of over 17,000,000, which is brutal and even better if you fully reload and get a headshot in Incarnon mode. To summarize, these are the mod bonuses:
GALVANIZED DIFFUSE: This mod grants you 110% base multishot and on kills, an additional 30% multishot for 20s, stacking up to 4 times for a total of 230%. (which increases the number of shells per shot and the damage much more)
PISTOL PESTILENCE + FROSTBITE : These 2 mods as they grant 60% Cold and Toxin and +60% Status Chance plus you get Viral damage 🦠 which for the Orokin works perfectly.
PRIMED TARGET CRACKER + Riven: Grants you 7.5x base critical damage and 10x in Incarnon mode. (so each shot hits harder)💯
PRIMED PISTOL GAMBIT + RIVEN : obtienes una probabilidad critica base de 104% y en modo incarnon un 152% de probabilidad critica lo cual ayuda con los criticos rojos
LETHAL TORRENT : Gives you +60% Fire Rate +60% Multishot (more firing speed and more projectiles per shot, which increases the damage much more.)
PRIMED HEATED CHARGE : This mod gives you an extra Heat damage 🔥 of 165%. (With this you get 2 damage elementals : Viral 🦠 + 🔥)
Build according to faction
BUILD CORPUS : 🧲 -> Spanish Photo Mods -> Translate into English
Here I focus a little more on 🧲 Magnetic damage than on status, since for these enemies I feel that I do better this way.

BUILD THE MURMUR : ⚡ + ☢️ -> Spanish Photo Mods -> Translate into English
These 2 types of damage are the best for these enemies since they are vulnerable to ⚡Electric and ☢️Radiation damage.

BUILD TECHROT : 🧲 +
-> Spanish Photo Mods -> Translate into English
Techrots are vulnerable to
Gas and 🧲Magnetic damage, and having the two together does quite a bit of damage.

BUILD GRINEER & SCALDRA : 🔥 +
-> Spanish Photo Mods -> Translate into English
Here I leave this build for both enemies, since both are vulnerable to
corrosive, in addition to the heat damage it is quite good

Synergies to Double the Damage
Warframe Abilities That can Help
( ROAR ) [Rhino]'s ability that grants a damage boost to your entire arsenal of Warframes for a short time.
( ECLIPSE ) [Mirage]'s ability that temporarily increases your weapon damage.
( NOURISH ) Grendel's ability that, in addition to providing Viral damage 🦠, gives you more energy and helps you with self-healing.
( FIREBALL ) [Ember]'s ability that, when you have the FIREBALL FRENZY mod, gives you additional damage 🔥 to your arsenal.
( THERMAL SUNDER ) [Gauss] ability that when you have the THERMAL TRANSFER mod gives you additional damage ❄️ or 🔥 or combining it will give you 💥. In addition to this it gives you more Fire rate
( ELECTRIC SHIELD ) [Volt]'s ability that, in addition to giving you a shield barrier, deals damage ⚡ and if you have the SHOCK TROOPER mod on [Volt], you can use the 1st ability and add extra elemental damage ⚡ to your entire arsenal.
Another good skill is [Wisp]'s Reservoirs, which improves fire rate and status chance ⚡
Warframe Arcana to increase damage
( ARCANE PRECISION ) : On Headshot: +300% Damage for 18s on Secondary Weapon
I HOPE IT HELPS, GOOD LUCK 👋