[Meglobob]

I think Mother of Serpents for her healing ability may be a good choice of pretender for Ma Ctis. It depends on how good a healer she is however. She could heal the diseased and afflicted.

Mother of Monsters as well. She gets +3 Lamias and Lamias are immune to miasma. The Lamia queen can extend your magic diversity as well.

Even without indies you can get all 8 paths of magic with Ma Ctis if you plan correctly and that does not involve what you put on your pretender. Some of those paths will however be only available for the endgame however, example air from faiery queen needs conjuration lvl 8.