the actual answer i was looking for is learning the lv4 limit, but ur close enough so i'll give you it.

enduring through the worst
and releasing the pent up fury --> taking attacks to fill ur limit, and using it to get the 2nd in a lvl
coupled with the destruction of hundreds, --> killing lots of enemies to get the first in the next lvl
and exploration, from sea to show, -->exploring to find the required item, sea being the gelnika for highwind and show being the battle arena
discovering the lost, perhaps hidden memories --> finding items which unlock something, in this sense hidden abilities
to unleash the true potential --> it's a lvl4 limit

i guess it's weimer's go then