Dcaptain23 has the general strategy down but i'll help out by posting the gear that i use
for this rank.

For Emil i got this setup

Weapon: Riot Spike: Critical 2, Regenerate 2, Fire Elemental

Body Armor you have two choices: Solitude and Pain Killer
Solitude offers nice hp boost and def while Pain Killer makes you more frail but gives you
the Glory effect (No flinch unless hit was a critical)

Head: Fencer's Bandanna: Critical 2, phys atk 2

Gloves: Dark Passage: Critical 2, phys atk 2

Accessories: Holy Symbol and blue amulet, the reason for the amulet is to shield you from
poison and paralysis as either of those will really cause you problems. The key thing in
this seteup is all those critical 2's making almost every 2nd or 3rd attack a critical to
make them flinch.

As for Marta i use a different strategy thus my gear likely differs from captains

Weapon: Dark Sphere: Sleep Attack 2, Dark elemental

Body Armor: Mythril Cloak : tp increase 2

Head: Wizard's Ribbon: Mental charge (doubles tp gained after battle ends) arte atk 2

Gloves: Mage Mittens: arte atk 1

Accessories: Mystic Symbol and Spirit Symbol

Marta can attack from a distance with Photon and Prism Sword on the slower monsters but
you'll likely run out of tp and soon be forced to fight up close to regain tp from
attacking physically.

This is why i use the Dark sphere for this, the Sleep effect that it occasionally does
works wonders on the Glory monsters because each of your hits won't be considered a
"wake up!" hit unless it is a critical hit.

If you know the spell Revive, save up the tp to cast that at the start of each battle so
if you happen to get killed by a nasty combo chain, you get a second chance.

Hope this helps but yeah its gonna be tough for you at your lvl.