Katrina is an “S” rarity hero from the “Blood Rose” faction. As a defense-type hero, she’s excellent at taking damage rather than dealing it.
You can unlock her by using “Prime Recruitment Tickets” at the “Bar.”
Rarity: 
Type: Defence 
Faction: Blood Rose 
Attack: 13,425
Defence: 16,575
Troop Size: 500
Skills
All-out Assault
“ She commands the Elite troop to unleash full firepower, lasting for 6 seconds. (Damage Factor: 1200 to 1241)”
Type: Active Skill
Upgrade Preview:
Star Level 1: Increases damage factor by an additional 150.
Star Level 2: Increases the duration by 1 sec.
Star Level 3: Increases damage factor by an additional 150.
Star Level 4: Supportive troop amount +2.
Star Level 5: Increases damage factor by an additional 300.
Explosive Bullet
“ Normal attacks’ damage factor increases from 900 to 920.”
Type: Normal Attack
Upgrade Preview:
Star Level 1: Increases damage factor by an additional 90.
Star Level 2: Increases damage factor by an additional 90.
Star Level 3: Increases damage factor by an additional 90.
Star Level 4: Increases damage factor by an additional 90.
Star Level 5: Increases damage factor by an additional 210.
Exploration Genius
“Idle EXP in exploration stages increases by 30% to 30.7%.”
Type: Global Effect
Upgrade Preview:
Star Level 1: Get 100 fuel for free per day.
Star Level 2: Idle EXP +5%.
Star Level 3: Idle EXP +5%.
Star Level 4: Fuel restoration speed +10%.
Star Level 5: Idle EXP +10%.
Potential Unleashed
“The hero’s attack and defense increase by 10%, and troop capacity goes up by 5%.“
Type: Exclusive Talent