Sampo is a Wind Nihility character who focuses on dealing damage over time (DoT). His Skill hits multiple enemies and can stack Wind Shear, a debuff that deals Wind damage each turn. His Ultimate hits all enemies and increases the damage they take from DoTs. Sampo’s Talent boosts his chance to apply Wind Shear whenever he attacks, while his Technique applies Wind Shear to all enemies at the start of battle.
Best Cavern Relics
(2) ATK increases by 12%.
(4) For every DoT the target enemy is afflicted with, the wearer will ignore 6% of its DEF when dealing DMG to it. This effect is valid for a max of 3 DoTs.
This set is especially good for Sampo because it boosts his DoT damage, since Wind Shear counts as a debuff.
(2) Increases Wind DMG by 10%.
(4) After the wearer uses their Ultimate, their action is Advanced Forward by 25%.
This set is also good for Sampo because it helps him take turns faster after using his Ultimate.
Best Planar Ornaments
(2) Increases the wearer's ATK by 12%. When the wearer's ATK is higher than or equal to 2,400/3,600, increases the DoT DMG dealt by 12%/24%.
This Planar set is especially effective for characters who deal DoT. For Sampo, reaching 3600 ATK is necessary to gain the maximum DoT damage bonus from it.
Best Stats

Body
Effect Hit Rate

Boots
SPD

Sphere
Wind DMG Boost

Rope
ATK%
Substats
ATK% / SPD / Effect Hit Rate / Effect RES
info
For Sampo to reliably inflict Wind Shear, he should have at least 64% Effect Hit Rate. He also needs to stack his ATK up to 3600 to gain the DoT bonus from the Revelry by the Sea set. Additionally, having 134 or more Speed helps him take turns faster and apply more DoTs.
Best Light Cones
SourceStellar Warp, Departure Warp, Character Event Warp, Light Cone Event Warp
Toiler
For every debuff the target enemy has, the DMG dealt by the wearer increases by 12~24%, stacking up to 3 time(s). This effect also applies to DoT.This is his best Light Cone for increasing his overall DMG output.
SourceStellar Warp, Light Cone Event Warp, Starlight Exchange, Stellar Convergence
Inheritor
Increases the wearer's DMG to debuffed enemies by 24~40%. When the wearer uses their Skill, the Effect Hit Rate for this attack increases by 18~30%, and ATK increases by 24~40%.This is his second-best Light Cone, designed to enhance both his DMG and ATK.
SourceLight Cone Event Warp
Wordly Affairs Leave No Mark
Increases the wearer's Effect Hit Rate by 60~100%. After the wearer uses Basic ATK, Skill, or Ultimate to attack an enemy target, there is a 60% base chance to inflict "Unarmored" on the target. While in the Unarmored state, the enemy target receives 10~18% increased DMG, lasting for 2 turn(s). If the target is under a DoT state inflicted by the wearer, there is a 60% base chance to upgrade the "Unarmored" state inflicted by the wearer to the "Cornered" state, which additionally increases the DMG the enemy target receives by 14~22%, lasting for 2 turn(s). During this period, the wearer cannot inflict "Unarmored" on the target.This is a good alternative Light Cone, designed to increase the damage enemies take when affected by Unarmored or Cornered states.
SourceStellar Warp, Departure Warp, Character Event Warp, Light Cone Event Warp
Self-Confidence
Increases the wearer's Effect Hit Rate by 20~40% and increases DoT by 24~48%.This is also a good alternative Light Cone for improving his chance to inflict DoT and increasing its overall damage.
Chaos Elixir
Increases the wearer's Break Effect by 20~40%. When the wearer uses their Ultimate, increases DoT dealt by the wearer by 24~48%, lasting for 2 turn(s). When a target enemy suffering from DoT imposed by the wearer is defeated, regenerates 4.0~6.0 Energy for the wearer.This is his best 5★ free-to-play Light Cone, designed to boost his DoT DMG while also providing Energy Regeneration.
SourceUnderground Shop, Echo of War, Memo-Keeping Light Casket, Light Cone Manifest
Semibreve Rest
Increases the wearer's Break Effect by 16~32%, and increases their DMG to enemies afflicted with Shock or Wind Shear by 16~32%. This also applies to DoT.This is a good 4★ free-to-play Light Cone alternative, aimed at enhancing his Wind Shear DoT damage.