Thayan Assassin Mastery

You are expert at slinking through shadows. You gain the following benefits:

• You gain a +1 to either dexterity, constitution, or intellect up to a maximum of 20.
• If you hit in combat with a Sneak Attack, you may choose to move up to ten feet as a free action. This movement does not provoke opportunity attacks. 
• If you use a skill you are proficient in to escape a grapple, you may add your proficiency bonus twice instead of once. If you have expertise in the skill, you may add your proficiency bonus three times instead of twice. This can be used a number of times equal to your proficiency bonus per long rest.
• When you are hidden from a creature and miss it with a ranged weapon attack, making the attack doesn't reveal your position.
• Dim light doesn't impose disadvantage on your Wisdom (Perception) checks relying on sight.