Unlimited invisibility on [Loki] using 0 Forma and no prime mods.=

The key to this build is [Narrow Minded] and [Fleeting Expertise], as these two will greatly help with reducing the cost of casting Invisibility, as well increasing the time you have to regenerate energy using your Aura.

Note that for [Fleeting Expertise], rank 4 is optimal, since Rank 5's 10% extra efficiency is not enough to reduce the Energy cost any further.

The rank of [Narrow Minded] is a lot lower so that it does not require too much Endo, which newer players may lack in. However, this does mean either Forma has to be used, or an Exilus Adaptor. Two Exilus Adaptors are given to players for free through quests.

Alternatives

If some mods still aren't owned (such as Narrow Minded or Fleeting Expertise, which are slightly more difficult to acquire), then any of the following tips may help:

• Using Flow allows for a very long Invisibility duration, though not infinite.

• Other duration mods, such as Augur Message, will also help increase total invis time.

• Lastly, if it's possible, getting more energy during a mission, or using less energy where possible (such as not using abilities when moving between spy vaults) will allow for effectively permanent invisibility.