EDIT: What a difference one word makes. Different fight actions really sinks this card in a lot of ways that makes a lot of this review make no sense!
In my opinion the best Discipline, but one you almost always take second.
Disciplines serve three functions for Lily: A slotless stat boost, a powerful 'supermove,' and protection from her weakness, which goes from being mid tier if you can't burn a discipline easily to trivial if you can.
The agility boost doesn't seem amazing. After all, Lilly is a guardian right? She should be killing things! But the thing is Lilly isn't actually super amazing at killing things with her kit, as being locked to melee limits her damage twofold: She can't get the literal 'big guns' that can push past 4 base damage with super amazing action efficiency, and she can't slot custom ammo (which tends to, late campaign, effectively just read "+1 damage).
Now don't get me wrong, I am a firm believer that you can still be a primary monster hunter with even a 3 damage weapon like a Cyclopian Hammer: Generally even in a 4 player game your not really expected to murder more than one monster a turn just because that is sorta impractical math wise or uhh... questionablly safe because your aiming lightning gun at your seeker's and mystic's general direction and if your blasting away for 3 attacks you have a 20% chance to just flat out kill a fellow investigator if they have less than the enemy's damage+4 health in that case on that turn, even assuming you only fail on autofail. Your flexes and even cluevers are going to need to be capable of making sure people don't literally die if you have to leave a monster on them for literally one turn, or else your team has problems way more fundamental than 'do I do enough damage.'
But lower damage weapons do make you a bit more volatile in other ways. Sure, its now generally more acceptable to shoot or stab in your friend's general direction, but now misses hurt more, because a higher proportion of your actions are likely required to kill the enemy. This means that teams with 'utility guardians' using stuff like Cyclopian Hammer or a Tommygun are going to need peel tools, and evasion is one of those. And hey, some of those 'chaos bag protection' tools your probably taking on Lily like your fancy candles can make it even easier.
But lets be real, your really taking this for the active and flip effect. The speed could literally not be there and this would be a highly competitive option, because the burn and flip effect on this combo just so well.
Guardians often aren't fighting literally all the time. Even in a 4 player game you generally have 'bursts' of activity, where 2 enemies are drawn at the same time or something where you and your flexes contain them and beat them down, and then a period of quiet. Boss fights tend to be short intense bursts of activity, rather than drawn out affairs: if your wailing on something for more than a few turns your either evade-juking it over and over to trivialize the fight, or your losing very badly. The ability to essentially get an entire extra turn allows Lilly to handle huge emergencies way better than her card pool may imply. Sure she doesn't have a flamethrower, but she can swing that cyclopean hammer 6 times a turn for a whopping 18 damage. And it can more easily be divvied up vs multiple enemies, making it actually easier for Lily to handle 2 enemies popping up solo than most other guardians, rather than harder. And, obviously, for boss fights, getting two entire turns of attacks, or 5 attacks plus an evade, generally sets you up to win: very few bosses can handle 8 actions worth of guardian attacks over two turns even before someone helps you evade tank or you start using things like Dodge.
But the flip effect also plays into this guardian loop of 'handle problems, prep for problems while also trying to help out in minor ways.' Because Guardians often will experience quiet moments (Unless, I dunno, your running with 3 Cluevers who literally can't even handle a rat in The Secret Name or something, in which case that is super not on Lilly) it is quite common to have turns where you just never encounter an enemy, meaning this is very easy to flip. Because the stat isn't super important to you, its also ok to let this sit unflipped if you constantly get a 'trickle' of enemies, which is sorta a nice place to be as a melee guardian. And because the effect is so easy to undo, it is fairly safe to let this flip when your weakness hits.
So this creates a very huge mid-campaign power boost for Lily: After 15 XP (generally 2-4 scenarios in, depending on how well you do and how much your mystic likes to delve) you suddenly get the ability to get double turns sometimes even every other turn. It is good enough I might consider it for my first snag for Lily, but I think she would much rather take Strength or Willpower depending on how you are constructing your deck