The Order of Secrets
Ultimates are most often ‘normal’ uses of a skill that by their nature always succeed with style. However they can only be invoked once per scene which makes them fairly limited in use. For instance a Stealth Ultimate could let you sneak past anyone in a scene who has a Notice skill of lower rank than your Stealth.
Some Ultimates combine limited aspects of unlocks, for instance an Ultimate Block can may redirect an attack back on the attacker. However this is not really an attack as such. Another example is a punch which can add aspect like ‘dazed’ to an enemy.