<Duality:> All Cosmology spells are divided into two versions; Cosmos and Chaos. When Casting Cosmology spells, always declare which version of the spell you are using.
Whenever a spell from Cosmology is successfully cast and caster had no Cosmology counter, it gains a counter matching that version; a Cosmos counter for Cosmos version, or a Chaos counter for Chaos version.
Non-Bound Spells from Cosmology have {their Casting Values reduced by 2} when cast by a Caster with a Cosmology counter matching the version of the Spell that is cast (i.e. Cosmos versions of spells have reduced casting values for casters with a Cosmos counter, and vice versa for Chaos). When a Caster attempts to cast a Cosmology spell of a version not matching its counter, it immediately loses its Cosmology counters.
At the end of each of your Magic Phases, replace all your Cosmos counters with Chaos counters, and all Chaos counters with Cosmos counters.