Portal Savant

You are expert at the teleportation spell of choice in the world of the Witcher. You gain the following benefits:

• You may cast the spell portal once per day without expending a spell slot. When you cast it this way, treat it as though it were cast with a spell slot of level equal to half your character level rounded up (maximum 9th level).
• You may cast portal as a reaction at any time. When you do so during another creature's turn, it lasts until the end of that creature's next turn.
• When you cast portal, you may have the nearby portal appear up to 30 feet away from you in an occupied or unoccupied space.
• You can perceive magical auras created by the portal spell for 1 hour after it is cast.
• Ability checks to recreate your portals automatically fail unless they are made by a creature with this feat. In that case, they suffer a penalty equal to your proficiency bonus.
• When you attempt to recreate a portal, you may add your proficiency bonus to the check.
• Whenever a creature passes through one of your portals, you may choose to eschew the chance it is instantly annihilated. You may do so a number of times equal to your proficiency bonus, regaining all expended uses upon completing a long rest.