Atavism

Atavism is a variant of summoning, but a very specialized one that's dangerous if you don't have a talent for it. It's the art of summoning an elemental in mental form into the mind of the atavist. The elemental can remain for much longer than normal, hours or maybe even days. The caster can wield the elemental's powers with their mana, melding the elemental's knowledge of their element with the caster's mana and skill.
Atavism can be dangerous, because if you don't have sufficient talent it is difficult to retain control even with a friendly elemental.
Atavism is a relatively new field of magic. It is believed to have been created by Sinera Kor within the last millennium.

Ruethwyn Sylaris has been expanding on the field, learning to use elemental energy, such as lightning, to gain some of the benefits of atavism for others without the normal risks.