Mercenary Helga — Epic Seven Earth Warrior: RTA Build, Counters & Win Rate

Mercenary Helga is a 3-star Earth Warrior built around single-target attacks that strip enemy Defense and an offensive team buff. Her two axe skills can apply Defense Down (75% on Attack Chain), and critical hits on Attack Chain have a 50% chance to extend her own buffs by a turn. Her ultimate, Cry of Victory, is a non-attacking skill that grants every ally Attack Up and Effectiveness Up for 2 turns, then pushes her own Combat Readiness by 50% to act again sooner. She has no passive, so her value lives entirely in landing debuffs and keeping those buffs alive.

Counters

Tanky, defense-stacked targets — Both her axe attacks carry a Defense Down chance, and her S2 lands it at 75%, stripping armor so she and her allies hit far harder into high-defense bruisers and walls.
Damage allies who need a fast opening burst — Her S3 hands the whole team Attack Up and Effectiveness Up, then immediately pushes her own Combat Readiness by 50%, setting up an aggressive turn-one swing and helping accuracy-hungry allies land their debuffs.
Sustained single-target grinds where buffs matter — Critical hits on her S2 have a 50% chance to extend her own buffs by a turn, so in longer fights she can keep her Attack Up rolling and snowball her own damage.

counterSetsuka59%

counterLone Wolf Peira54%

Countered by

Immunity and cleanse holders — Her whole pressure is the Defense Down debuff; an immunity buff blocks it outright and a cleanser wipes it, so allies lose the shred window she was built to open.
Dispels and buff theft — Her S3 team buffs and her self-buffs are her real value; an enemy that dispels or steals buffs erases the Attack Up, Effectiveness Up, and crit edge she set up.
Buff-shortening effects — Anything that shortens buff duration cancels out the one-turn extension her S2 crits provide and clips the 2-turn team buffs early, neutering her offensive boost.
Burst before she rotates — Her team buff and only Combat Readiness push sit on a 5-turn cooldown with no passive safety net, so a fast team can kill her or her carry before Cry of Victory comes back up.

Skills

S1Armor Rend

Attacks with an axe, with a X chance to --decrease Defense-- for 2 turns.

S2Attack ChainCD 2

Strongly slams the enemy with an axe, with a 75% chance to --decrease Defense-- for 2 turns. A critical hit will have a 50% chance to extend any buffs granted to the caster by 1 turn.

S3Cry of VictoryCD 5

Encourages all allies, increasing Attack and Effectiveness for 2 turns before increasing Combat Readiness of the caster by 50%.

Soulburn −10 soulsExtends duration of buffs granted by this skill by 1 turn.