Continuing with “but why?”
Omni– : all, in all ways.
Ambi– : immediate surroundings, both.
Omni– : as in “omnipotent” – all-able or I guess – almighty. Omniscient – all-knowing.
Ambi– : as in”ambiguous” – double-meaning, I guess double-sided in a sense. Ambidextrous – someone with an ability to use both their hands just as well as we, mortals, use our dominant.