"Ultimate unlock" refers to achieving the highest or final level of access, accomplishment, or understanding in a particular area or context. It signifies reaching the pinnacle or ultimate goal in a specific endeavor. Full definition
This years ultimate unlock, which is available once you have collected all the Disney Infinity 3.0 characters is * drum roll * Sora's Keyblade from Kingdom Hearts. (iheartinfinity.com)
This signature weapon joins Yoda's lightsaber (Disney Infinity) and Luke Skywalker's landspeeder (Disney Infinity 2.0) as the third ultimate unlock. (thehdroom.com)
Following the pattern of ultimate unlocks hinting at future Disney Infinity content, wouldn't it be cool to get a wave of Kingdom Hearts 3 Disney Infinity 4.0 figures next fall? (thehdroom.com)