These builds use weapons and armor that are unlocked by the time you clear Chapter 5 of the story.

Best Fated Adventurer Builds

Weapon
Heavy BowgunRadiant Datura Blaster III
AttackElementAffinityDeviation
382Blast1910—
Armor
HeadRadiant Jagras Helm III
ChestKing Beetle Thorax II
ArmsRadiant Jagras Vambraces III
WaistRadiant Barroth Coil II
LegsKing Beetle Crura II
Active Skills
Great Jagras's Roll (Set)Monocerus Divinity (Set)
Capacity Boost Lv3Insight Lv2
Charge Up Lv1Blessing Lv1
Geo Expert Lv1Bento Lover Lv1
Breaker Lv1Battle Spirit Lv1

Takes Capacity Boost, which pairs well with bowguns, and combines it with gear that raises affinity so you can deal high damage at all times.

Best Pepper Builds

Water Element Build (Gliding + Normal Ammo Focus)

Weapon
Heavy BowgunRadiant Jagras Cannon III
AttackElementAffinityDeviation
268Water1340—
Armor
HeadButterfly Vertex II
ChestHunter's Mail II
ArmsRadiant Jyura Vambraces II
WaistHunter's Coil II
LegsButterfly Crura II
Active Skills
Butterfly Bond (Set)Wilds Mastery (Set)
Ammo Enhancement Lv4Airborne Lv2
Health Recovery Lv1Geo Expert Lv1
Ballistics Lv1Water Damage Up Lv1
Insight Lv1Improviser Lv1

A setup that pairs well with Pepper, combining the Hunter Set, whose Ammo Enhancement boosts Spread Ammo damage, with the Butterfly Set, which raises your damage while gliding. Ammo Enhancement Lv4 also raises elemental attack, and together with Water Damage Up, it boosts your elemental damage as well.