Killed in a particularly spirit-dampening, freak tragedy, (involving being burned, starved, and bitten by a venomous talking fox. Don't ask.) Merskelly found undead life again when one of her magic eyes survived intact.
She used her magic to piece herself together again slowly, and learned to cope with being undead. Using robotic implants, cellular reconstructed growths of her skin and limbs, she can periodically change into more humanoid, amphibious or aquatic type appearances.
Though most of her efforts to build herself are purely scientific, she uses mer-magic too.
Merskelly was once an alien mermaid, and all mermaids get their magic from their song and their scales. But alien mermaids get their magic from their eyes. Without their eyes they cannot see music or detect lights in space...or exist. Every so often Merskelly will use her eye to help her with important tasks and alter her appearance. She keeps her eye safely locked away inside her head at all times, and sometimes even creates a decoy to occupy her other socket.
Merskelly came from a distant planet in space, where she lived and swam and made happy memories with the many sea monsters, pirates and ghosts of her world. But one day she found an injured fox from a world beyond her own, on the shores of her world and took care of it.
However it was sick and very temperamental, often nearly killing her with its venomous bite. It never got much better although she felt she had healed it's wounds the best she could, and sadly she died trying to return the fox to the world from whence it came, deep within the woods of dimensional doors, gates and traveling furniture.

When she woke up, all that was left of her was her eye and her head. Alone and lost in the woods, with no trace of the fox to be seen, she rolled and rolled back to the sea, with the helpful aid of a cute, orange alien bird, who made sure she made it back to the water. She thanked the bird and said goodbye even though it looked sad to see her sink into the depths of the ocean. And began to work on her new body straight away.
With her magic eye and new body she decided to conduct further research and go on short expeditions into the alien worlds next door to her, where she no doubt, would enjoy learning new things, trying to understand the strange people and creatures she encounters, and occasionally admiring the many different kinds of pasta in existence. But the one thing Merskelly had hoped to accomplish, was to improve and heal not only herself but to help others to heal from similar aching and tragic pasts, and give them something worth holding onto...while likewise seeking something to treasure and remind herself, that she can be alive after all...