Ok so let's say the warrior makes it to the crown of command and then a character that can attack with Psychic combat makes it shortly after.

Does that mean from then on the combat will be psychic combat?

OR do the character tke turns using Psychic combat and battle?

Or something else?

Warrior on his turn engages the other character in battle, while the other character on his turn has the option of engaging the Warrior in battle or psychic combat.

yes that makes sense thanks