"Looking at stars and knowing their natures is necessary for charting any new courses to planes we don't have regular contact with. It's not terribly exciting. Necromancy's all working with the dead, but it's not just animating corpses and manipulating bones; finding ghosts and talking them into accepting a psychopomp is in there as well. Rank five gets you lichdom, which is... the most secure immortality short of phoenixes, who I'm only pretty sure exist. Transmutation's pretty broadly useful, it's mostly fairly specific changes but you can do a lot with it. Low-rank demons, up to rank three, are much more useful than dangerous, and working relationships with the fringes of Hell come in handy for a coven, but at rank four and five you can get yourself in trouble - summoning a wrath demon is rarely wise and never safe, but some people feel cornered by something else dangerous and give it a shot anyway. I'm considering rank four for the other type it gives me, servants who are paid in my own sloth, but I don't intend on ever learning the fifth, that's making deals with greater demons and it is, absolutely, Faust territory."
"Portals come in two types - Gateways and Rifts. Rifts are temporary, flimsy, and cheap to make. Initially you get about six inches across and sixty feet range, but those both double each rank, they get more durable, and you learn to make one-way rifts to elemental Proximae - fire and ice at second, lightning storms at third, water at fourth, and sucking void at fifth. Fifth also lets you get permanent rifts and a stronger connection; hotter, colder, more electric power, more water pressure. Gateways you start out with one at most, fifty mile range, takes a ritual of sacrifice - anything with real economic value - to create. You can do back-and-forth touch-and-go objects instead of doorways if you like. The number active roughly doubles per rank and the distance quadruples until the limits drop - distance at fourth, number at fifth."