When it comes to expressing the concept of "seat of authority," there are numerous synonyms that you can use in your writing or speech. These include phrases such as "power center," "command post," "rule hub," "governance nexus," "dominance hub," "central control," "regulation nucleus," and "mastery core." Each of these terms carries a different connotation, from the idea of an established power center to the more futuristic-sounding mastery core. The choice of synonym will depend on the tone and context of your communication, but each offers a vibrant and engaging way to convey the idea of a centralized locus of control.