Benevolent and loving, Semel is very patient with her children. She cares for their fate and the fate of her planet but is not above actively interfering when she believes it suits the greater cause, such as returning Helen to life. Brief History
Dawn Of Time: The Creator spawns two "daughters" - Semel and Ehrun.
A Millenia: Tired of his "daughters" fighting, the Creator sends them to Haven and binds their fates to the fate of the planet.
Two Millenia: The first sentient life appears on Haven. Semel and Ehrun are worshipped, eventually leading to a war which wipes out the population. This cycle continues for several hundreds of millenia, until the sisters tire of fighting and retire to their temples.
Several Millenia Later: Helen arrives on Haven, by now a desolate abandoned world. She claims it as a safe retreat for fugitive Telepaths, and begins creating a city. Her actions do not go unnoticed by Semel, who keeps a watchful eye on the human woman
Twenty years later: Helen dies. Semel seeks her out in the place beyond, and offers her a deal. She will break Helen's bonds and return her to life, in exchange for Helen becoming the Guardian of Haven and cheif warrior against Ehrun. Helen agrees and is reborn with no memory of the arrangement - marked on the back of her neck with Semel's seal Magical Skills
In theory, Semel's powers are boundless. However, the Goddess is bound to the planet of Haven, and most of her skills will only be possible there. She can, and has, even return someone to life, but the spirit must be willing or the process is impossible.