Steadfast

Steadfast rogues are streetwise and observant, and have learned (perhaps the hard way) that the people who live the longest are those who look after themselves. They can preemptively react to threats, scan the area around them quickly, and lock down stealthy foes.

Critical Moment

Starting at 3rd level, you've practiced reacting quickly to danger. You may add your Intelligence modifier to initiative rolls. In addition, you may move and take actions and reactions on the first turn of combat even if you are surprised.

Surveillance

Starting at 3rd level, you can use an action to scrutinize your surroundings and assess danger. You learn whether you are being watched, whether there is a hidden trap in your line of sight, and whether any creature is concealing a weapon, as long as this information is not hidden magically. In addition, you have a +10 bonus to your passive Wisdom (Perception) and passive Intelligence (Investigation) scores. You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Crowd Control

Starting at 9th level, you won't let just anyone slip by you. You have advantage on attack rolls made as part of an opportunity attack. 

Window of Opportunity

Starting at level 13, you can overextend yourself in combat to strike decisively when it's needed. Once during each of your turns, you can choose to give yourself advantage on an attack roll. If you do, you can't take reactions until the beginning of your next turn.

Counter Intelligence

Starting at 17th level, you have lived against the odds and developed an almost supernatural sense of awareness. You gain the following benefits:

• Whenever an ally within 30 feet of you is surprised by an enemy, you may make your choice of a Wisdom (Perception) check or an Intelligence (Investigation) check contested by the enemy's Dexterity (Stealth) check. If you succeed, you warn your ally, allowing them to move and take actions and reactions on the first turn of combat.
• Whenever you enter combat and the enemy is not already surprised by you, you may make a Dexterity (Stealth) check contested by their choice of a Wisdom (Perception) check or an Intelligence (Investigation) check. If you succeed, you slip out of sight, and all enemies are surprised on the first turn of combat.