Selene is a great villainess with a clear motive. She seeks power, god hood, revels in corruption, desires heirs, and craves immortality without dependency on a vampiric ability to achieve it.
Best stories-- her desire to subjugate Magma & Rachel and her contest for the Upstarts.
In stories with her over the last decade or so, writers seem to not use her psychokinetic abilities to animate inanimate matter. Or her full sorcerous prowess.
Her deathlike power is a counterbalance to Storm's more lifelike powers-- yet no direct conflicts. And her and Rogue share slightly similar life energy absorption powers, yet only one direct fight which showed Rogue vulnerable.
Love to see her return and be established as an arch rival to Storm or Rogue. Think it could make great stories.