Rogue - Mist Weaver
(DnD 5e Rogue Subclass)
The techniques of these rogues origin from the Fey realms and its ever changing environment. After practicing within obscure fogs they emerged changed, able to bend the ephemeral cover to their will. They strike from the mists and are never seen again.
At 3rd level, as an action, you can cast the fog cloud spell centered on yourself without expending a spell slot. It lasts for 1 minute, has a 15 feet radius and does not require concentration. While moving through the fog you do not trigger attacks of opportunity. Using this action again dispels the previous fog cloud.
Starting at 9th level, you can choose to use this ability as a bonus action, if you do so, the fog only lasts until the end of your turn.
Eyes of the Hunt
Also at 3rd level, you can see through obscurement (such as the one caused by fog, mist, smoke or clouds) and non-magical darkness as normal sight up to 15 feet.
At 9th level you can see this way up to 30 feet.
At 9th level, you are used to manoeuvring through the mists, and know how to discern truths from illusions. You gain proficiency in Insight and have advantage on saves and checks against illusion spells.
At 13th level, when an enemy targets you with a melee attack roll while you are in the area of the fog cloud, you can use your reaction to vanish right after the hit. You teleport and appear behind the target where you can make a single melee weapon attack roll. If you used your Sneak Attack feature this round, you can’t apply it to this attack.
At 17th level, when you use your Misty Presence Ability the fog cloud moves with you. In addition you can choose to expand its radius up to a maximum of 30 feet, or shrink it down to 5 feet (no actions required). In addition you can teleport as a bonus action anywhere within the area of the cloud, which then recenters on you.