Portals

A hub of portals where a character can enter from any and go through to any other— it is a trade or culture hub.
It creates a door within a physical object (e.g. a building or wall), pushing it open will open it - allowing you to pass through to the other side.
There are many ways to open a portal. Voidish can do it by thought and will using their magic, Guardian Angels can do it freely without any consequences, Hub Portals have a specific time where it'll open and close.
Who has access to it? All Voidish citizens can use portals, other races have to get a special class distinction passport within Intansin.
Inanimate objects and radio/soundwaves can be sent through.
What is the cost? The physical toll for doing too many portal openings within the space of twelve minutes is extreme fatigue and irritability. Average citizens can only do this four or five times within the space of five minutes in between. If a citizen were to over-exert themselves, portals will not be able to open again by their touch (for the hub portals) and their magic will nullify.
Can it be opened from both sides? It is possible to pull someone through to your side but it is not possible to open up a portal and let more than one person or two people come through from another side without them opening it on their side.