If you're having trouble, before pressing fight use ironskin or invincibility potions on everyone, skip till you have 20 ap, then use a chili pepper. It's easier to maintain a combo if you just attack with only one person, most swords, dual swords and spears can "combo" by itself.
Get a dragon crest shield or hire a hunter with one so you don't get killed from freeze or stun. Hire one hunter with the highest hp and another with the highest str. At chapter 3 you can fight Viegraff to recruit him. Then at chapter 5 get Gabriel from the "divine messenger" special mission, his slay ability instakills almost anything. At hunter level 10 you can buy invincibility potions, with a couple of those and Gabby you can win any mission. "Defeat trio assassin" and "Sir George Request" gives the most hr points per area afaik so you can level fast.
Okay game, did all the challenges, including the friggin ridiculous 600 area one, just using the special mercs.
Didn't have to do any stupid grind for any weapon that needs 99+ materials. Didn't need any weapon really. At hunter level 10 you get invincibility potions. Make the avatar a rogue for the extra ap, give him the nullall shield, and just stick him in the back.
I liked it. How about adding another layer to story, such as it's a simulation, like the matrix, or too cliche ? Also, the comments need a spoiler warning haha.
 "The Bravest Hunter"){kind=icon}
 "Swarm Defender"){kind=icon}
 "Antichromatic"){kind=icon}
 "Bois D'Arc"){kind=icon}
 "A small talk at the back of beyond"){kind=icon}