Minor spells let you detect their presence even while inactive. You can open and close simple triggered portals. You can even teleport small objects short distances by opening momentary portals.
Major spells can teleport man-sized objects short distances and reactivate dormant portals. They can temporarily make an opaque portal transparent or cloud a normal one. They can also modify a portal so that it will jam when the next person travels through it. They can create one end of a two-part portal or open one entirely if the other end is already in place, but it won't be stable.
Dramatic spells can create stable portals between locations. They can render a portal inactive or clear out a jammed one. They can teleport a small group of people to somewhere in the same realm. They can modify existing portals, such as adding triggers or changing their destination.
Legendary spells can open a permanent portal to a new location without having to do anything there first. They can teleport a large group of people to anywhere in the same plane or another. They can modify all portals in a plane, including shutting them all down.
Flesh
Minor spells can boost healing rates, cure minor diseases, evaluate someone's health or change someone's physical stats in a minor way for a brief period.
Major spells can make flesh regenerate rapidly, cure major diseases, detect specific traits (such as illness) at great range or change someone's physical stats in a major way temporarily. Used to harm, they can open gaping wounds in people.
Dramatic spells can bring back the recently deceased (provided that their body is mostly intact), cure or inflict major diseases on large groups of people or change someone's into another creature temporarily.
Legendary spells can create deadly plagues that ravage kingdoms or cure them. They can turn a group of people into another form permanently. They can bring back the dead even if they have been dead for awhile or their bodies mostly destroyed.