Loki

Loki is a trickster warframe, relying on subterfuge and deception to cause chaos on the battlefield.

Loki’s passive is Wall Grapple. When Loki latches on to a wall, he can stay grappled longer than any other warframe.

Decoy

Loki’s first ability is Decoy. He creates a holographic copy of himself that draws enemy fire until it dissipates or is destroyed. Loki can only place one Decoy at a time. Any Decoy that Loki places will destroy the previous.
Decoy
Invisibility

Invisibility

Loki’s second ability is Invisibility. Loki becomes invisible to his enemies for a period of time. While invisible, Loki won’t be targeted by enemies but they will still try and retaliate to damage by firing at Loki’s last known location. Even though Loki is invisible, enemies can still hear him when he fires his weapons, if they are not suppressed. Invisibility also applies to any companion that Loki brings along.

Switch Teleport

Loki’s third ability is Switch Teleport. Loki will switch places with a target, enemy or ally. If targeting an enemy, they will become confused for a moment upon being teleported. Loki’s Decoy is a valid target for Switch Teleport.
Switch Teleport
Radial Disarm

Radial Disarm

Loki’s fourth ability is Radial Disarm. Loki emits a wave of energy that stuns and permanently disarms all enemies within range. Enemies that cannot be disarmed, mostly infested units, will take damage from this ability instead.

Loki Builds

Ability Strength mods affect the damage that Radial Disarm does to enemies that cannot be disarmed. Ability Range mods affect the range of Switch Teleport and the radius of Radial Disarm. Ability Duration mods affect the duration of Decoy and Invisibility.

So, all things considered, here are some builds you may want to try on your Loki: