Mage Hunter

From years of tracking down and fighting magical creatures, your senses and reflexes are sharpened against them.

You have advantage on Intelligence (Arcana) and Intelligence (Investigation) checks for recognizing or understanding magical phenomena. Such as e.g. magic seals, traps, disguises, apparatus, invisibility or triggers.

When inside 5 ft. of a creature, that is trying to teleport away from you, you can use your reaction to grapple the creature. On a success, you are teleported with the creature. 

You can do this up to a number of times equal to your proficiency bonus. Regain all used after a long rest.