Standard Skill
Agave fires a homing projectile at the target, which deals PBAoE Electric Damage on hit.
Using the skill continuously increases its phase - projectiles fired at higher phases do more damage with larger AoE, but use more S-Energy.
The damage increase from phase increases is massive - Phase 4 deals around 3.5x the damage of Phase 1.
If Agave shoots her gun or doesn't use the skill for 2 seconds, Phase resets back to 0.
For each hit with her Standard Skill, Agave gains Personal Flair (which is used for her Ultimate).
This is the number above her S-Energy gauge in the bottom-left of the UI.
Each hit gives Agave 1 Personal Flair per Phase level.
If her standard skill hits a destructible part, it also damages another destructible part. (Or deals more damage if only 1 part is available to hit)
Hitting a destructible part also reduces the next skills S-Energy cost by 25% per part hit.
If a destructible part is destroyed, then Agave gets 50% reduced S-Energy consumption for 3s.
If the skill defeats a target, her next skill usage with 5 seconds doesn't use S-Energy.
Agave can move whilst using this skill, but it isn't quite as fast as moving normally, meaning she has lower mobility than just running about normally, but mobility is still decent as she can still move freely whilst using her Standard Skill.
Standard Attack
Agave shoots her gun.
Agave recovers S-Energy per hit with her gun.
Since Agave does not naturally recover S-Energy whilst she's on the field and in combat, landing hits with her gun is her only in-combat method of recovering S-Energy.
She does recover S-Energy when not in combat though, so for casual gameplay she can clear a group using her skills and then just run to the next group, and her S-Energy will almost always have fully regenerated by the time she gets to the next group.
Note that the Skill Damage buff from her 4* and 5* signature weapons are removed whenever Agave shoots.
Ultimate Skill
Agave deals AoE damage in front of her - the more Personal Flair stacks she has, the more damage dealt.
Note that the damage of Agave's ult isn't quite linearly proportional to the number of Personal Flair stacks she has.
Agave's standard skill rotation tends to end up giving her around 30 Personal Flair, but this can vary depending on certain things (notably M1).
Using three ults at 30 Personal Flair deals 20.5% more total damage than one ult at 90 Personal Flair.
Agave loses her Skill DMG buffs when she shoots, so make sure to always use her ult after using her Standard Skill - never use her ult directly after firing her gun.
Her 4* weapon needs 4 standard skill casts to max its buff. Her 5* weapon needs 3 casts.
If Agave has 20 stacks of Personal Flair or more (which she should always have if you're doing her rotation properly), then after using her ult her next Standard Skill usage within 10 seconds skips straight to Phase 4.
As such, she should use her standard skill until she runs out of S-Energy, and then ult immediately.
This allows her to keep her Skill DMG buffs from her gun and have them apply to her ult, whilst also skipping to Phase.4 after regaining her S-Energy, which allows her to not waste S-Energy using weaker Phase 1/2/3 casts.
Whilst you can use her standard skill, shoot, repeat until her Personal Flair stacks are at max, and then Ultimate, this results in less damage than just ult-ing immediately after her S-Energy runs out.
Her ult has some base damage, so the more casts the more damage
E.g. Two ults at 50 Personal Flair deal more total damage than one ult at 100 Personal Flair.
Not using her ult would mean that after shooting she would have to start her standard skill from Phase.1 again, wasting damage by not making use of the buff that allows her to skip to Phase.4.
As such, getting to 100 Personal Flair is just a DPS loss, so avoid doing it and instead just Ult when she runs out of S-Energy as per the 3-step rotation listed in the "How to use Vidya - Agave as a DPS" section above.
Support Skill
Agave's Support Skill causes her to deal Electrical DMG + Paraylze (for 2s) in an AoE in front of her.
Note that the stun and damage from her Support Skill are not really very useful - you're using it for the ATK buff [below] only, really.
This uses 20% of Agave's S-Energy. If this causes Agave to use more than 10 S-Energy, Agave gives the entire squad a 2% ATK bonus for 15s per S-Energy over 10 she used.
Given that this skill has a 15s duration, Agave will always be at full S-Energy when it is used.
With Agave's passive +30 max S-Energy and her 4* or 5* weapons +20 max S-Energy, Agave has a max S-Energy of 100, meaning 20% of her S-Energy is 20 S-Energy.
Using 20 S-Energy means Agave uses 10 more than 10, so her Support Skill gives the entire team a 10 * 2% = 20% ATK buff.
Given that this is a 15s buff on a 15s CD, provided you spam it off-cooldown it's basically permanent.
ATK tends to get quite a few buffs (Logistics, Logistics substats, Manifestation levels, other support operatives....) and is quite a saturated category, but despite this, 20% ATK is a good bonus considering it's basically permanent and doesn't require much investment.
Agave also gives a pure-ATK boost, which almost every main DPS operative in the game benefits from.
Many other operatives like Celestial Swan, Nightglow, Starshine, Phantasia, Kaguya, Exuvia, etc. all have some restriction on who can use their buffs.
Provided Agave has her 4* or 5* weapon, she can provide this full 20% ATK buff, which is a very low barrier to entry.
(Without one of her signature weapons that increases her max S-Energy, it's still a 12% buff)
Agave doesn't get any bonus to her Support Skill from her Manifestations, and her Neuronics and Deiwos also don't functionally change it, so Agave having her 4* or 5* weapon is all that she actually needs to be a decent support, and even without any investment at all it's again a 12% buff, which can benefit all operatives.
Is Agave a great support?
Not really - compared to other support operatives like Celestial Swan, Nightglow, Riptide, Kaguya, Starshine, etc., Agave does fall short, but Agave provides a useful benefit with 100% uptime and zero investment outside of just having Agave and hopefully having one of her signature weapons.
Will Agave make it onto an endgame team as a support? Not unless Parts Breaking is needed, no.
What Agave will do though is provide an extremely easy-to-get buff that benefits basically all dps operatives, with 100% uptime, which is enough to make her an ok support for new players, or for players who don't want to put investment into supports.