I’ll explain it and some of the issues with AI and skills as well as balance.
Party Members Skills Explained
First, lets address the issue of the combo system. This is the X (first press) > X2 (second press) > X3 (third press) setup.
Unfortunately, this game features absolutely no bonus or incentive mechanics of any type whatsoever to use this features. It doesn’t have the % dmg bonus for combos like Star Ocean Till the End of Time or the anti-spam penalties and other mechanics of Tales of Arise. In short, you can literally just put the skill on X1 and leave X2 & X3 (same for square, B, or whatever) empty.
Extending on this prior point further is the fact that the skills have laughable balance issues. In short, you simply need to equip the single best skill you have for a character and no others in most cases. For example, Raymond’s two best skills are his two starting skills (yes, hilarious I know). Notably, this is Boulder Crush (great at not missing airborn targets or while he is also airborn, high dmg, decently fast despite the initial delay, very spammable due to low AP cost of 2).
His other basic slash becomes really valuable later on once you have high end crafting (or earlier depending on where you are) once the dmg is high enough to already 1-shot targets due to its faster attack (no point doing 500% more dmg than necessary while using a slower attack if it already dies). His Demon Gate (or w/e final skill) is only good for really the bird bosses due to the teleport effect. The rest of his skills are simply “bad” putting it nicely compared to more choice descriptions they honestly warrant. Thus he only needs 1-2 attack skills for 99%+ of the game and you don’t need to set them as a combo because X1 spammed 3x is the same as X1 > X2 > X3.
Most characters suffer from severe balance issues with their skillsets like this. Albaird has his demon orb whatever it is called gravity attack that makes equipping any other offensive skill pointless. Midas skills are typically also super poorly balanced so odds are you will just equip his fire air jump slam attack. Marrielle is dead obvious with her beam attack being hilarious because someone obviously said screw balance and brought a nerfed but not nerfed enough Maria’s attack back which should never have been seen again. Etc.
This doesn’t include some support effects that may be useful to toss on one of the “empty” buttons. Example. Raymond X Boulder Crush / Square the basic slash (or remove it so AI doesn’t use it until strong enough to benefit, up to you) / Triangle his self buff skill (that one with ultra short duration is actually crazy OP, lasts until you stop attacking). Btw, I just realized X is jump iirc so pretend X is any other attack button like Circle or w/e. You could put X “Hold” as something like a Fresh Sage so if Nina dies Raymond will revive her so Nina can continue reviving everyone else / healing as an emergency option (or just do this if on a really hard fight, otherwise leave off).
Last, while you can earn more AP beyond a 5 AP limit the AI can never accomplish this. Say you earn 15 AP on Nina and swap to Raymond. Nina does not get that 15 AP. She is still at 5 AP. Nothing the AI can do can ever increase that AP past the limit of 5 nor are there any effects in the entire game that increase this limit for the AI. This further hampers the combo system because if you have a combo that is, say, 2 AP > 3 AP > 2 AP you will fail to use the third press because you’ve run out of AP after the second press.
This is most notable with Nina who has particularly high AP costs on some of her skills. Further, she has one skill if I recall that has a bonus if casted after another and it is a buff skill. Ignore that feature. Not only is it not necessary and that buff isn’t that good, but it can negatively influence her AI behavior (particularly healing spam because she may buff instead of healing as fast). This makes Nina the most important one to follow the 1 skill per button (press and hold can be considered different buttons) rule so that Nina’s AI works properly without running into AP combo problems and also behaves in the way you expect. Some of her skills, btw, have decreased AP cost as they get leveled up which can make her more competent in battle without having to wait for AP to recover (doesn’t change the combo rule of 1 skill per button, but less downtime between AP recovery).
Nina’s Tips as Example
- Nina’s heal should be set to the tiny chime AoE that she tosses out and it keeps auto healing in a small AoE. Not only is it faster to toss several of these and produces superior overall healing on a specific target it makes her more mobile overall with set and forget so she can run to other characters and do the same. This makes her more flexible on top of being able to focus on using her other abilities. Further, the AI actually does not handle her large healing AoE skill which has to be held… as it tends to stop it prematurely (plus it can be interrupted from being hit and AI may not make best judgement). The exception is if you are directly controlling Nina you CAN use the large AoE healing to build up the AP bar for yourself if you plan to keep actively using her in that fight (only equip the large AoE heal when doing this, which will probably be never because she is super broken when setup right and the only fight I can even think it might be worth controlling her is the hardest fight aka 2nd super boss post game). Not a huge priority to level. Even at rank 3-4 it heals very well.
- Nina’s best skill is her revive. Try to level it to max level with a higher priority than other skills and even reaches 100% full recovery on everyone in range from dead at max level with zero resource cost other than AP which is hilariously broken and can be gotten the moment you get Nina (baffling balance design). It couples well with her skill that teleports in a ultra massive range everyone to her even when they’re dead so she can easily collect everyone for a team-wide revive. This combos further with her invulnerability barrier which can upgrade to have enough duration to last the entire revival time… nearly guaranteeing it.
- The invulnerability skill that creates a large AoE shield is pretty great and probably the #1 priority to upgrade, even for AI as it can somewhat competently spam it. It makes it last much longer. I would do the revive skill as upgraded after (even at rank 1 revive is still mega-broken, get the revive skill first tho in terms of acquisition order).
- She has a dmg debuff which works very very well on bosses.
- I found the invisibility skill worthless. As she is typically passive she rarely draws much aggro compared to damage dealers and when setup right she runs around so much the enemy has issues chasing her anyways. Further, well… below tip.
- Nina should be built full on tank. No emphasis on INT at all. Her heals don’t scale well off intelligence stat and just their base stats are enough to even manage high end post game builds with 40k+ HP non-issue not to mention the 100% healing revive. However, what happens if you build your healer to be as mega tanky as possible, highly resistant (or outright immune/heals) from every elemental dmg type, and immune or highly resistance from most or the worst status effects (notably 100% immunity to confuse is a MUST, it disables all factors equipped when confused)? You get a tank with absurd base scaling and already full HP AoE revives that becomes nearly unkillable. In fact, it can actually tank the fully upgraded 6 winged super bosses on chaos if setup right, especially with her debuff skills. Nina is probably the most disgustingly balanced healer any JRPG has ever seen, beating even quick cast Tear (esp as Nina has absolutely no resource limitation and can drop dmg to literally 0 taken).
There are two passives so ridiculously good they should be learned on every character that can acquire them (which is most). First, the flinch skill is very useful to prevent being stunlocked such as you will see in the fight where you first meet Midas at the gate and the chain gun / missile spam from many robots can super stunlock you. Further, if you don’t flinch you will not be knocked airborn. I don’t know the full numerical mechanics of dmg calculation when airborn but I can tell you that you take a huge increase in dmg when knocked airborn by the enemy. The other skill is the First Aid where you have a % chance to recover a percentage of your max HP when taking dmg. This pairs well with First Aid and in general is broken. It heavily reduces strain of needing to heal and with high enough defense, notably Nina… lol, can render character’s quite literally immortal.