Hi, Runna. Since your signature says your hair is coarse, I'd be really careful about conditioning with proteins, like the yoghurt, eggs, and coconut oil. I have coarse hair, too, and have to be careful to only do protein treatments perhaps once a month.
If you think your hair needs protein, I'd check the ingredients of the moisturizing conditioner you listed to see if it contains protein, and if not, I'd use it and add one egg, the mashed up banana, some olive oil, and some melted shea butter. If you don't need protein now, I'd avoid the egg (and the conditioner if it contains protein).
One of those immersion stick blenders or a regular blender would work great to mix up these ingredients, since they may not get fully incorporated by hand.
You might enjoy this NC article on porosity
if you haven't seen it already.
All the best with your recipe, and let us know what you use eventually.