Planeswalker

A piece of a ether - known as a Planewalker Spark - has ignited in your soul and you have become a planeswalker - a mortal with the ability to travel between the planes of the Multiverse. You gain the following benefits:

• You learn the plane shift spell and can cast it without expending a spell slot and without material components. Once you cast this spell in this way, you can’t cast it in this way again until you finish a long rest. You can also cast the spell using spell slots you have of the appropriate level. Your spellcasting ability for this spell is Constitution.
• In addition, when a creature you can see casts plane shift, you can use a reaction to also cast the spell (expending a use of this feat or a spell slot as usual) and follow in their immediate wake.
• You gain the ability to magically sense the presence of a planar portal. As an action, you can detect the distance and direction to the closest planar portal within a mil of you.