Shadowlynx is a Dark damage dealer that has a lot of mobility. She has good AGI and Luck, making her quite fast and evasive, and increased move + jump + Hayate (from Samurai sub job) to navigate the map easily. She won't be hitting hard since most of her offensive moves has low to mid multiplier, but she's good at some PvE farming quests since her skills have good range, and Dream Within a Dream to clear chain missions.
After EX, she gets a huge increase to her base attack, putting her at #1 out of all the units in the game, and will stay there for a few months by looking at JP units. That being said, she doesn't have any defensive piercing ability, so she won't be the highest insane damage dealer you want her to be. Her AGI and Luck are also pretty good making her comparable to 2B (speed and evasion only, not the damage). Maidens of the Rose also exists to give her some extra stats.
However, the 2 upgraded skills adds an interesting niche to her use. The passive upgrade to Shadow Runner will additionally give an increased chance to inflict stop and blind, which can be quite deadly in PvP, or even certain cotents. Shadowbind's upgrade gives her a rare debuff that can reduce an enemy's single target resistance by up to 30, potentially increasing your other units' damage by a lot, but the move only has a range of 1. Job lvl 25's new move is an offensive skill with good range that can inflict blind, making her more viable in pvp since she already has high AGI and Luck.
Depends on what are you using her for, previously during the judgement ordeal event for ribbon, i think you might wanna use her for chain so dream within a dream. For guild battles and arena, I dont really recommend it.
which type of card should i use on shadowlymx agility or luck
I'm in the minority, but I like Dragoon. You get her speed mixed with the damage they can bring. Just make sure you don't target someone who will move before you attack. But usually the wait is only one or two turns later.
she should be rated as S tier, she has a better master ability than Kitone, she's great in PvE, She's very mobile, fast, has range attack, evasive, and good Damage. If you are farming, u don't really need to overkill an enemy, u just need enough dmg to 1 hit an enemy. Imagine having a unit that is fast and can move around the map easily that hits hard, u can clear a level faster and you can farm mats faster.
Sub dragoon seems fun since she is fast can attack very far.
Thou sub as samurai complements her ninja class the most since it's evasion and slash attacks too imagine shuriken and hien both range to your melee damage. Blade soul and shadow runner passive you won't regret.