For those who want to get through the game with minimal pain but do not want to skip battles!

Heraldsville:

Make your way to Mr. Smith's house. Explore the town at your leisure as all chests in this area mainly give starting healing items. Leave the village and make your way to the bridge. For an easter egg, run away from the slime encounter. Then walk up to the slime again and then run away again. Walk leftward and you'll be able to walk past the slime! Almost....

Panshaw area:

This area is pretty light on chest goodies. Visit the STEALSMITH, do not buy anything, then explore at your leisure.  Find the bandit girl living in the tent for a slightly different dialogue when you meet them again in the woods. Leave the area and talk to the guard at the bridge. Make your way to the manor, then to the sparkling area in the forest.

The Woods:

Loot the blue chest, talk to the slime. Use Spark to one-shot the entire hoard. On the next map, look for a hidden passage to the left between the trees.

Encounter 3: Bandits

Have Harold use Spark and Lucius use Encourage on Harold for the first two turns. Use Spark until one enemy is left and Fire spells should take them down. After that, head on inside Lucius' mansion.

Visit the tent in Panshaw after this fight! The bandits are now gone and you can now look the Thief's Sack inside! Equip the Thief's Sack on Harold to rack up ridiculous amounts of gold.

The Pass:

Very simple area with two encounters: A minotaur with a hoard of bats, and a Vermillion bird with an Alex cameo.

Encounter 4: Minotaur

Have Harold use Spark and Lucius use Encourage on Harold for the first two turns. Spam Freeze on the minotaur

Encounter 5: Vermilion Bird

Have Lucius Insult the bird ASAP. Their Blast spell will interrupt Harold and Lucius with stuns. Have Alex use a couple of Holy spells before finishing the bird with his regular attacks. Alex has a very high crit rate with his regular attacks.

Jedburgh area:

Look for a blue flower on the left edge of the map. You'll find a Seizer's Salad in that hidden area. Explore at your leisure.

Easter Egg: Wander around the wheat fields on the right-hand side of the map to find a grasshopper telling you to watch where you step.

Encounter 6: Jacques and Ashe

Have Therese use Incendiaries on Ashe, cast Freeze on Ashe until he goes down. Have Lucius Debate Jacques as he is the tankier of the two. This is a simple battle. After that, make your way to the fort.

The Fort:

Look out for a chest containing a Canteen item on the map immediately after the fort! There is also an Iron Ring item in a hidden exit to the top of that same map, though the item isn't very useful.

Encounter 7: Behemoth

Use incendiaries to bring down the behemoth's m.defense. Spam Freeze. After that, spam High Caliber to prevent the behemoth from moving.

Windborne:

Not much to this town, mostly serves as a pit stop made to slowly introduce Oldhar which is our B story.

Encounter 8: Black Tortoise

Insult the tortoise ASAP since their Toxic spell will slam your party with status and debuffs. Use Piercers twice and then spam High Caliber to prevent the tortoise from moving.

Roam:

When possible, loot the Cute Bunny Outfit at the pub and give that item to Harold (lol). Find the Cute Hair Clip at the magic school and give that to Marcia.

Encounter 9: Guards

Really easy breather battle to give a break from the constant minibosses. Use Spark/Fire while Lucius uses his regular attacks.

Encounter 10: Jacques and Ashe

These guys have literally the same stats as the first encounter with them. Use Piercers to reduce their defense and have Harold use his Earth spell to exploit their debuffed physical defense.

Portsmouth, The Ship, Southpoint:

Get the Seizer's Salad in the house to the bottom-left of Portsmouth.

At the Ship, explore around to find a Seizer's Salad in the storage area. Chat up your party members at your leisure. To progress to the next town, talk to the captain.

Buy a couple of Moonshines at the bar at Southpoint. These are our best healing items! Leave the town and make your way up through this run towards the next town.

Encounter 11: Troll

Hit the troll with a water spell first turn. Spam fire moves.

Encounter 12: White Tiger

Insult the tiger ASAP because its Plasma spell removes buffs. Use Flurry for the first three turns then spam Freeze until the tiger goes down. Spam Incendiaries as Harold will be the primary damage dealer this fight.

Encounter 13: Feathered Beast

This miniboss has a massive lightning weakness but Harold should not be using his lightning spell here. Have Therese use Piercers twice; Harold should spam Earth. Their debuffed defense will allow both Marcia and Harold to do sizeable damage

Paradise:

There are a couple of stat-boosting items in the right-hand side of the area. The upstairs of the food hall also has a couple goodies as well. Explore at your own leisure before making your way upwards to the temple after doing the woodchopping quest.

Easter Egg: When possible, also leave Paradise and make your way to the top-most part of the island in the overworld. You will find a hidden area with a Seizer's Salad chest.

Encounter 14: God

Oldar should use Toxic twice. On the third turn, God will then go down immediately from one Annihilate spell due to their Darkness weakness and halved defenses.

SWORD Sanctuary:

The chests in this area before the Epic Dungeon mostly have healing items.

Encounter 15: Earth Spirits

Water spells.

EPIC Dungeon:

In the Epic dungeon, you will find a Magic Circlet in the door at the metal section. The Horneddoggo encounter is an easy fight despite it hitting one of your party members hard but only once. Feel free to grab the optional Evil Spiked Armor in the farthest right door too.

Encounter 16: Azure Dragon

This fight is a curveball due to the dragon having resistances to fire, lightning and ice attacks, and a Radiation spell that deals a fixed 500 damage. Use Piercers and Earth attacks.

Loot the blue chest at the end of this dungeon. The red chest contains a Seizer's Salad (dropped by the mimic)

Final Resting Spot:

Dump all your gold on Mushrooms to max out Harold's magic stat. Give him the Magic Circlet item found in the Hornedoggo encounter. Harold should now be an unstoppable beast!

Final Encounter

Insult Usluci ASAP as he carries a lot of nasty debuff skills!

If this walkthrough is followed to the dot, Harold should have a magic stat in the 300's range. Have Therese use Assist on Harold as Harold uses a Storm spell. Shamar should go down on the first turn before they do anything. Use the Storm + Assist combo again and Usluci should go down. Use a Piercers + Earth combo for the remaining bosses.

Once you win, enjoy the fireworks!