Fire 
Physical elements, who belongs to the Source Citadel faction. Their position in combat is Front.
Katas is a DPS by having a single target attack that can stun and draw her ultimate skill, regardless of being in the deck or discard. This Ultimate skill hits all enemies in range. Her full potential unlocks at Resonance 4, where she will be able to generate her Second Ultimate that deals massive AOE damage. As a starter, she will greatly help you push content, given that one of her cards can generate 5 cost.
Playstyle and Key Mechanics
Katas’ role is about dealing as much damage as she can for both Single-Target and AOE situations; however, they come at a cost, given that they require high cost. Thankfully, making her a Leader alleviates that high-cost requirement for her Ultimate skills and Derivatives. As long as you can cycle her combos properly, you will surely have a good time playing her in your roster.
Main Cards
For starters, we have [Blazing Slash], which is a single-target attack that can apply [Stun] and [Blaze] to the target. This can also add a [Purgatory Unleashed] card to your hand from the Deck or Discard pile. Alternatively, when you make Katas a Leader, this will now reduce the cooldown of her Leader Skill by 10 seconds.
Next, we have the [Energy Bubblegum]. With how high the running cost for Katas is, this at least paves the way for her to cycle through them. A really great cost generator with the base of 3 and can increase it to 5 once you unlock Resonance 1, which is not a hard investment.
Lastly, her bread and butter for dealing AOE damage [Purgatory Unleashed], this has 2 more Derivatives, which are an upgrade turning [Interrupt] into [Stun] and being able to trigger [Ignite] or [Slash]. When using [Purgatory Unleashed], there is a chance it can generate [Umbral Fulgor], her most devastating AOE Attack. However, this is only possible by Unlocking Resonance 4.
Derivatives
Umbral Fulgor - An AOE attack that can only be generated by [Purgatory Unleashed]. This is an insanely high damage card with a staggering 20000% multiplier for Fire Damage, as this can also inflict [Slash], which can increase its damage by another 50% when enemies have [Chill] or another 100% increase if they have [Freeze]. It also creates [Wildfire], which can do damage over time for 6 seconds.
Investment
Katas Awakenings are incredible, as it's just about increasing her damage, and starting from Awakening 2, it already highlights its focus on [Umbral Fulgor]. Let's break down each of her Awakenings to understand what we’re saying.
Awakening 1 - Every time you use her skill card, she increases her ATK by 3% and this can stack infinitely.
Awakening 2 - Using [Energy Bubblegum] increases the next 4+ Cost Red card’s damage by an additional 100% more damage. One thing to note is that only the 2nd and 3rd iterations of [Purgatory Unleashed] and [Umbral Fulgor] are the only available Red cards for her to benefit from this effect. Thus, make sure that the buff doesn't get consumed by something like [Blazing Slash] or another Red Card with a lower cost.
Awakening 4 - Turns her already powerhouse skill [Umbral Fulgor] into a giant nuke by consuming Black cards and [Shadowcraft]. For each card consumed, it provides 10% more damage for [Umbral Fulgor] with a cap of 200%. A very good stopping point if you want dupes of her.
Awakening 5 - Improves the cycling of [Umbral Fulgor] and [Purgatory Unleashed]. This Awakening enables [Umbral Fulgor] to draw [Purgatory Unleashed] or instantly use it if she is the Leader. It is great, but not really recommended.
Resonance
Resonance 1 - Increases the Cost generated by [Energy Bubblegum] from 3 to 5.
Resonance 2 - Katas gains [Invincible] a 1-time lifeline upon taking a big hit. Convenient as she is positioned in the frontline.
Resonance 4 - A must upgrade for her, as this is the only way she can generate [Umbral Fulgor]. Activating this Resonance, there is a 30% chance of her generating [Umbral Fulgor] when using the skill [Purgatory Unleashed].
Resonance 5 - Greatly improves the use of her Ultimate/Leader Skill by making the 3rd iteration of [Purgatory Unleashed] transition to the 2nd iteration of [Purgatory Unleashed] instead of going to the base one, which leads to her dealing more damage.
Synergies
❗ ❗ ❗ The Synergies mentioned here are merely samples. Taking their core mechanics as an example, you can use many other characters as replacements or other synergies. ❗ ❗ ❗
Valentine - Valentine has cost-effective [Ignite] skills which can help reduce the cooldown of [Purgatory Unleashed] when used as a Leader Skill. She also has [Prayer], making it instantly activatable.
Kaleya - Incredible healer and utility, her heals summon a [Drone] healing an ally and applying [Ignite] to a random enemy, a great tool for reducing the cooldown of [Purgatory Unleashed] when used as Leader Skill.
Rina Von - A reliable frontline tank that can greatly improve Katas' survivability by redirecting most incoming damage onto her and controlling enemies to prevent them from doing damage.
Tennie - Tennie can apply an AOE [Freeze], making [Slash] attacks more effective, which is exactly what [Umbral Fulgor] inflicts, so expect insane amounts of damage when you use it with Tennie’s [Shaved Avalanche].
Stella - Great support option by reducing the cost of the cards, making cycling efficient.
Arcana - Improves the Cost regeneration and being able to redraw used cards from the Discard pile, really nice if you want to fish for [Energy Bubblegum] for more Cost generated.
Gear and Affixes
Some examples of overall good equipment choices for Katas. For specific picks, please check the respective teams.
Weapons:
UR Scorching Spike: Whenever [Ignite] is inflicted 8 times or [Blaze] is inflicted 4 times, inflicts [Wildfire].
SSR Unbewusstes Probe: Whenever you play a Red card of cost 3 or more, random enemy receive 3% less healing. This effect stacks up to a maximum of 75%.
SSR Volcano: [Ignite], [Blaze], [Wildfire], and [Inferno] dealt deal 25% more burning damage per second. This effect stacks.
SSR Severe Punishment: Deals 15% more Fire DMG.
SR Viscera Collector MK 0: Using [Leader Skill] restores 0.4 Cost. This effect stacks.
R Gardener Multi-Tool: Playing a Red card increases ATK by 0.5%. This effect stacks.
R Mass Projector: Using [Leader Skill] increases ATK by 1.5%. This effect stacks.
Armor:
UR Lucid Dream Fiber: Wearer's Red cards heal the wearer for 2% of the damage dealt.
SSR Simulated Stars: Using [Leader Skill] restores 5% HP. This effect stacks.
SSR External Memory Matrix: Max damage taken per hit is 33% of Max HP.
SSR Mecha Armor: Whenever [Slash] / [Rend] inflicted by wearer deals damage, restores HP equal to 5% of the damage dealt.
SSR Black Rock Armor: Reduces wearer's final DMG taken by 10%. This effect stacks.
SSR High Dimension Construct: Generating a Black card restores 5% of Max HP. This effect stacks.
SR Resonance Fiber: When own skill card is used, restores 2% of Max HP.
Accessory:
UR Dawncloud Seal: Max Hand Size +1.
UR World Line ß Box: Draws a card whenever you encounter a wave of enemies, prioritizing wearer's skill cards.
SSR Mobius: Cards in your hand are replenished 0.25 seconds faster. This effect stacks.
SSR Divinity Seal: Gains 2 Cost at the battle's beginning. This effect stacks.
SSR Fengshui Tactical Drone: For every 8 cards used, increases ATK or DEF by 2%, up to a maximum of 50%.
SR Magic Spring: Restores 0.02 Cost per second. This effect stacks.
R Harrison Device: Playing a Yellow card restores 0.3 Cost. This effect does not stack.
Affixes
Using [Leader Skill] restores 0.2/0.3 Cost. This effect stacks.
Using [Leader Skill] restores 2/3% of own Max HP. This effect stacks.
Using [Leader Skill] increases own ATK by 0.5/1%. This effect stacks.
Increases own ATK by 1/3%. This effect stacks.
Increases own ATK by 10/30. This effect stacks.
Increases all own trigger rates by 1/5%. This effect stacks.
Restores 0.01/0.02 Cost per second. This effect stacks.
Playing a Red card increases own ATK by 0.2/0.5%. This effect stacks.
Increases final DMG dealt by 2/5%. This effect stacks.
Gains [Hyperarmor] for 1 second when using own skill cards. This effect stacks.
Wearer's [Rend] cards deal 3/5% more damage. This effect stacks.
Deals 3/5% more Fire DMG. This effect stacks.
[Stun] dealt lasts for 1 second longer. This effect stacks.
Inflicting [Wildfire] restores 0.05/0.1 Cost. This effect stacks.
[Ignite], [Blaze], [Wildfire], and [Inferno] dealt deal 5/10% more burning damage per second. This effect stacks.
[Ignite], [Blaze], [Wildfire], and [Inferno] dealt last for 1 second longer. This effect stacks.
