Marcus: This Hyperion fascist thinks he's safe cause he's got a shield. Spoilers: he isn't.

Cheapskate: It's only a matter of time until Jack burns this city to the ground, you resistance scum!

(If any other than shock weapon is used ...)

Marcus: See how shields resist fire? If you really want to break a shield, you'll need a shock weapon.

(If any other than shock weapon is used again ...)

Marcus: No, no, no -- switch to another weapon and hit him again, da?

(Vault Hunter fires at the target with a shock weapon.)

Marcus: Take that, Jack-lover! A few good hits from a shock weapon will zap a shield away quicker than you can say "buyer's remorse!

(Vault Hunter turns in the mission to Marcus.)