These are known move patterns for all of the enemy types in the game. Every one of them has been confirmed by me personally. No guesswork has gone into them. I make no claims that every pattern is here, so don’t stake your life on that.
The letters represent what the enemy is doing for each action during a turn. They do not represent what you should be doing. You need to use the action triangle and use Guard against Attack, Break against Guard, and Attack against Break. Guard can also be used to reduce damage from an attack Skill or most Noble Phantasms.
A, G, and B are Attack, Guard, and Break.
W is Wait. The enemy is doing nothing.
S is an unknown Skill.
SA is an attack Skill.
SS is a support Skill.
EX is the enemy’s Noble Phantasm.
* is unknown.
The details of what the Skills do are beyond the scope of this page. For the Boss Servants, you can find information to help with that in the main walkthrough.