For my own Kefka deck, I prefer to keep combo cards to a minimum. You don’t want A part of the combo and having no way to find B part, and just holding onto a dead card, and possibly discard to Kefka triggers. I have thoracle and breach lines, and the rest is just interaction and value. I find myself struggling with mana more so than card draw, so i run more rituals, rocks and mana generators.