*Disclaimer* This isn't as much as a guide as a few tips, because without fail this is the worst character to play as in this game.
Missions: Kill only who you need to finish the mission if your Commander/Main Base is under attack, defend, immediately, purely as this character is awful and you won't want to replay any mission, I learnt the hard way.
Combat: I found the easiest way to beat an officer is-
If not guarding: Spam your basic Quick Attack (X) until the combo finished and knocks them to the floor, rinse and repeat.
If guarding: use your XXXY attack you'll kick the "Kemari" (Football) around your body in a circle, unlikely to hit the officer with the blast but will break his guard- see above.
After 5 agonising missions you'll be done with this joker. The only thing which made this bearable for me was his halfwitty repartee.