Go to the veldt with Gau in your party there you can get into battle with ervy monster youve seen on game so far. Use the leap with Gau, keep walking around after the next battle he'll appear and he'll of learnt that rage.
soem more side events for you:
aquire gogo and umaro plus mog collect all dances
get the ragnarock esper
cursed shield
mog side quest (in narshe naming mog aquiring umaro)
kefkas treasure/tower
STRAGO'S UNRELIEVING PAST
loads mroe i cant be bothered to list atm mroe to come soon
