Ofcourse you can't do all of this because your doing a solo Marche but here's some points that may help:
That sage with reflex is nothing:
-Combos will hit no matter what- if you're going to go physically at him, that's the only way to go if you haven't disabled him yet.
-Reflex is useless against anything except 'fight'
Redmage:
-Return magic is no problem... don't do/use any magic- 'fight' her or use a skill/technique.
-She could have cure- destroy her second.
Paladin:
-Run at the paladin and KO him as fast as you can- don't let any one with life on the engagement alive.
-Paladins are short ranged- if you aren't confident of beating him with your characters, wait for him instead and prepare.
Time Mage-
- 1)Aim:Legs 2) Run to another opponent
OR
- 1)Aim:Arm 2)Kill
-Demi halves your HP. If he just does Demi with no interuptions, he can never kill you.
Some crappy advice:
-Archers could play a big role in this- abilities (including R ones) are disabled if aim:arm hits.
- If all else fails- it's telling you to level up.
-if the sage hasn't mastered reflex yet, learn steal:armour if you can and steal the mirage vest off him.