Gas Gathering: speed increase
Hunt March: speed increase
Hunt ATK Up: Hunt ATK increase
Use him early to do campaign mode, upgrading him to 71. Because Marshall is an economy hero, his skills are passive. Because of this do not reset him once he reaches level 71, but upgrade him no further.
He should be enhanced to +5, which give you a +30% to Gas Gathering speed, +30% to Hunt March speed, and +30% to Hunt ATK.
He can be obtained in Noah’s Tavern