Passionlip

Due to the synergy between Passionlip's three skills, leveling all of them and keeping their cooldowns relatively even is highly advised. However, the focus may shift if Masters prioritize Passionlip's tank/control potential or if using her as a general AoE pseudo-Berserker with a Starting NP Gauge CE.  

• Breast Valley is a fantastic defensive skill that allows Lip to take at least half or less damage from average neutral attacks. The debuff immunity can also negate the demerit of Trash and Crush. Although these effects are on a three-hit system, the buff duration is long enough to be refreshed on cooldown at max level.  Although the damage cuts scale well with level, the buff duration and static debuff immunity stacks push this skill towards being leveled last. Do try to level this to 6 before Trash and Crush reaches 10 otherwise Master can potentially stun Passionlip with Trash and Crush on a second use. 
• Masochistic Nature A is one of the stronger taunts in the game. Despite the one-turn duration, it has a strong built-in defense buff and a surprisingly short 4 turn cooldown at max. Combined with her other skills, Lip will take almost no damage against neutral enemies while gaining a good amount of defensive NP. This skill gains a generous attack buff that only activates when Lip is below 50% HP post-Interlude, which is another boon towards helping Passionlip's offense. The reduced cooldown is invaluable to increasing Passionlip's ability to control the fight, so level it first if intending to use Passionlip as a tank, else level it second.
• Trash and Crush EX features another strong Defense buff in addition to an equally strong Attack buff and the coveted Ignore Invincibility. The instant-kill on-hit is a bonus at best with it's extremely low activation rate, but the other effects give much needed unconditional offense for three turns. Unfortunately the defense buff lasts only for 1 turn, and Masters may need to weigh using this early in combination with her taunt.  Level this first as it's Passionlip's only offensive steroid, and a strong defense buff as well.

"I still don't understand, but I've decided to face these feelings properly!"  

Shy, introverted, but loving blindly while hating equally, the Alter Ego Passionlip debuts in the CCC SE.RA.PH event as an AoE Buster tank. With a taunt on a low cooldown, a variety of defense buffs, and even more tools like Ignore Invincibility and team healing, Passionlip will shine in teams that can benefit from her ability to control the fight, while they support her in return.

The majority of Passionlip's gameplay revolves around tanking, taunting, launching her NP that heals the team, and tanking more. With all three skills up, Lip can almost completely negate basic attacks from most enemies. Her short cooldown taunt enables her to redirect damage from her team and gain good amounts of NP from absorbing hits. Once she fills up her NP gauge, launching her NP has the benefit of not only healing her team, but producing a good amount of stars as well through its bountiful 12 hits per target hit count.

Endowed with a generous amount of passives, Passionlip's double-dipping on Magic Resistance and Goddess Core for 35% Debuff resistance provides ample debuff resistance when Breast Valley is on cooldown. Her surprising access to Presence Concealment is the crux to her surprising amount of star generation on NP, stars she can then use to better effect through her small Independent Action critical damage buff. Most importantly, Passionlip has the High Servant passive, which doesn't do anything but exert a feeling of composite deity superiority.

However, there are a few caveats to this monstrous beauty. Passionlip's triple Buster deck is decent for damage, but inconsistent when it comes generating stars of NP. Passionlip has to rely on her taunt and allies to charge her NP. Likewise, Lip has a generous attack stat and an offensive buff, but she is still held back by the Alter Ego 1.5x damage modifier against cavalry class Servants. Her proportionately anemic HP stat and Alter Ego class also means that she will be reliant on her defense buffs to tank the majority of enemies as she will not profit from a defensive class bonus.

With weaknesses in generation and damage that can be remedied by Buster supports in spectacular fashion (especially Merlin), Passionlip is a curious and honest girl who will defend her team and take care of them in turn. Just like her plot development, she is dependent on teammates and support, but once she gets going she really shines as a both an off-tank, and an AoE Buster damage-dealer.

Buster Alter Ego Alternative

With her decent offensive stats, triple Buster deck and her AoE Buster NP, Passionlip makes good use of the Alter Ego class' flexibility for farming mixed cavalry nodes without the Berserker fragility. Full Buster-based options are rare for both the Assassin and Caster class, and Masters with a preference for Buster decks will find comfort in her ability to deal full class advantaged damage to Foreigners and Berserkers, and 1.5x class advantaged damage to cavalry-class Servants. Still, Passionlip will require access to both her Interlude and her Rank Up to truly compete with full class advantaged options in terms of damage. 

Tankiness and Taunt

Passionlip can gain up to 60% in defense buffs on top of a 1000 damage cut in her base kit alone. As flat damage cuts are applied after the % damage cut, Passionlip  often takes almost no damage from average enemies' attacks. The short cooldown taunt complements her defensive prowess perfectly, allowing precision control of the battle by directing all damage to Passionlip for one turn at a time. Lastly, her NP helps to recover any missing HP for her and her team, especially after its Rank Up.

Strong Tools for Offense and Durability

Passionlip has a variety of tools that aid her as a tank/off-damage dealer.The debuff immunity from Breast Valley shrugs crippling debuffs including Trash and Crush's demerit, with a strong 35% debuff resistance for whenever Breast Valley's stacks are on cooldown. Meanwhile, the Ignore Invincibility on Trash and Crush allows her to deal damage no matter what - the enemy is unable to escape from her. Lastly, with Presence Concealment Passionlip can take advantage of the hit counts on her Quick, Extra, and NP to generate a surprising number of critical stars. 

Alter Ego Limitations 

With generally no defense class advantage, Passionlip's durability is noticeably impacted in her tank role, especially in tandem with her lower HP. Since Alter Egos only resist Foreigners, Lip will be taking neutral damage from most other classes and double damage from Berserkers. Likewise, her 1.5x effective Alter Ego modifier caps her offensive potential compared to dedicated class counters, which results in lower NP and basic attack damage outside of critical hits.

Limited Generation Potential

Having a thematic triple Buster deck helps offsets some of Lip's poorer Alter Ego offenses at the cost of creating fewer opportunities to generate NP and star. Although the combination of her taunt and defensive NP gain partially remedy this situation, Passionlip will still require support in order to pull off her powerful NP in a reasonable amount of time. 

Passionlip is primarily focused on tanking for the team, launching her NP for its additional effects and Buster start, although with enough buffs she can be used for decent farming as well. Buster Performance Up not only benefits most of Passionlip's deck in terms of much-needed damage, but also provides a slight boost her star generation on her NP. Starting NP Gauge makes up for Passionlip's inconsistent NP gain and allows her to launch her NP quickly, which is especially great for farming situations. NP Gain CEs are also viable, to boost the NP gain she receives from being hit while under the effect of her taunt. Lastly, defensive options such as Defense Up, Guts or Invincibility will synergize with her tanking kit and allow her to continue tanking for longer.

• Limited/Zero Over / Joint Recital /  Verdant Sound of Destruction: Buster Performance ups such as these will almost always benefit Passionlip's offenses.  While typically straight buster up is preferable due to her lower critical potential, Joint Recital isn't a bad option either to make use of her NP's critical stars.  
• Kaleidoscope / Partake with the King / Holy Night Supper: Kaleidoscope is the prime recommendation for farming or turn-1 NP's, especially since Passionlip lacks an NP battery.  Partake with the King (or First Sunrise) combines the best of Buster buffs and starting NP, while Holy Night Supper is an alternative that synergizes better with common Buster Supports.
• Conquering the Great Sea of Stars / Chocolate Angel: With a mix of Buster Performance and NP Gain, Passionlip can generate impressive sums of NP with her taunt while still dealing good damage.
• Volumen Hydrargyrum / Grand New Year / Chaldea Lifesavers / Holy Shroud of Magdalene: Without the typical class advantage to tank with, for longer battles Passionlip will benefit from increased defensive options. Invincibility will work especially well for dodging Boss NP's with her taunt, while Grand New Year provides an all-in-one package for switch-ins or so. Capping her defense buffs with the Holy Shroud is a powerful option against males as well.