Shade

Shade is a Stealth Sentinel which comes with its own weapon, Burst Laser. The Shade's cloaking ability can last indefinitely as long as an enemy is inside activation radius. The cloak only activates if an enemy is in the activation radius sphere for the cloak, and Shade's view of the enemy is not obstructed by nearby objects (i.e. Shade is behind an object inside the sight radius that is obscuring it from seeing the enemy, even if your warframe can see the enemy it won't make a difference). Activation is not dependent on the direction that Shade is facing. Warframe abilities will not bring you out of stealth and you will remain hidden, as long as another enemy is close by.

Note that infested Runners will still explode when you are next to them, regardless of being cloaked, and enemies such as leapers, rollers, or ancients that have activated their attack (such as a Leaper getting ready to charge) will still hit you after you cloak if you do not move out of the way. On infested levels, take care around Runners as the explosion could knock you out of cloaking range.

Consider Shade when choosing to be a medic for your team, as running up to downed players without firing weapons can allow you to heal them while cloaked, reducing risk to yourself, an alternate method to using the Sanctuary mod in case one is not available to you.

Acquisition
Shade can be bought for and the blueprint for.

Sentinel Loadouts
See the user build section for builds using this sentinel.