Arcane Rhythms are represented as words with power, rituals, or even chants with magical power and intent. It is easier to give intention to words, after all. Also, when you try to make an energy resonate with you, you find it easier to call it out than to simply think it.
After all, the Threads are in the environment.
They are usually used to create a massive amount of Power Runes before a fight, so that you don't run out of supply, but during long-duration fights, it's common to see fighters use these types of rituals for massive attacks.
Now, why are they called Magic Rituals? It's simple: because your chant or words are directed to the God you want to get that magical power from.
There are four basic chants.
Addressed to the God of Fire: Oh, God of Fire, heed my call and bring me the joy of summoning a portion of your power; the power to burn my enemies.
