Toggle Background Color
Wind elemental medium-range linear attack with wide and tall area of effect
Like most of the Folks Ellen gets in this chapter, Telanthera's attack has a significant delay before it starts moving. This can make an effective Wind barrier as long as the enemies are in front of Ellen and don't have long-range attacks. Otherwise, you don't get much out of Telanthera that you wouldn't get out of Garbera. The ranged attack may be a bit harder for enemies to avoid than Baolwind, but I've never had a problem hitting enemies with Baolwind.
How to fight it: Keeping your distance is best, although that's no guarantee of safety. Telanthera uses a number of highly annoying wind attacks and also shoots claws at you with limited homing capability. Then it disappears and reappears elsewhere. Try to be patient and whittle away its health with Bullseye and Barrager, or Slash attacks like Fraxinus or Grab Bag.
Thunder elemental medium-range charging attack
Muscari, unlike many ranged Folks, charges with its entire body rather than launching a projectile. This means that if anything hits it along the way, it will stop in its tracks. The long pause before it launches gives the enemies plenty of time to interpose any form of attack, negating Muscari's effect. I'm sure there are situations where it works, but I can't think of what they would be. It can score multiple hits if it gets through, so that's something to admire.
How to fight it: This is one of the few cases where Telanthera can be useful, as long as you're not surrounded. If you can knock Muscari out of the air, you'll have a chance to hit it with just about any Folk - Wind or Water is particularly effective. Muscari is vulnerable to Sleep, so Habetrot makes it much easier to fight.
Destroy elemental short-range attack with wide sweep
Gladiolus is really strong and really expensive. Without the delay before it attacks, it would probably be a great Folk. As it is, Fomoire is probably better in every respect.
How to fight it: Gladiolus tends to chase you down relentlessly and either swing a fist downward, spin its fists around, or sweep two lasers in front of it. If it's floating, guard its attack and fight back with a Destroy attack of your own. The other attacks can be dodged by keeping out of range. Hit it enough, and it'll fall apart like a Spriggan. Capture it with the Beat method.
Non-elemental medium-range charging attack
For a charging attack, Agapanthus has a surprisingly small range of attack. It'll run right past close targets without even hitting them, and when it does hit, it rarely gets the same Folk with both fists. Add in the delay before it attacks, and there's really no point to Agapanthus at all. The most infuriating thing is that as aggravating as it is to fight, it drops Green Quartz.
How to fight it: While it's wearing its armor, only Destroy attacks will be effective. Hit it a few times, and its armor will break, leaving it vulnerable to other elements, although Destroy continues to be effective, so there's no real pressure to switch. Capture it with the Stop-and-go method.
Slash elemental short-range attack with wide sweep, chargeable
Finally, a Folk that's not bad. It's just redundant. With Ogma, Fraxinus, Grab Bag, and even Answerer, I think Ellen's Slash element needs are pretty well covered by now. Bergamot can charge its attack, but so can Alraune if you have the time to do that, and Alraune can score multiple hits per attack.
At least it's still better than Beithir.
How to fight it: Fighting at close range is risky, because Bergamot will usually scuttle backward, out of the way, then hit you with its tail. Long-range attacks will negate that attack, but you'll still need to watch for its ice breath. If it rears up, move to the side or back to get out of its range. Capture it with the Timing bethod.
Destroy elemental short-range attack
Finally, a good Folk from this chapter. Ammobium still has the pause before it attacks, but it's not like Ellen has a glut of other Destroy attacks that would make Ammobium irrelevant. Unlike most of the other Folks in this chapter, Ellen isn't frozen while Ammobium is out, and the delay isn't really that long. The best part is that it knocks down most Folks when it hits them, and the kind of Folks you'd use Destroy against are generally best knocked off their feet as often as possible. It's not perfect, but it's a great addition to Ellen's arsenal.
How to fight it: It's mostly a less slashy version of Bergamot that can be captured with the Shot method, so it's not a threat even if it's not alone.
Non-elemental long-range projectile attack, chargeable
Charged projectiles are rarely effective, because most enemies that you need to fight at range move too quickly for the projectiles to target. Cyhyraeth isn't all that bad in general, but the selection of non-elemental attacks is great enough, and you can't get Cyhyraeth until the final chapter, after which you'll need to have enough Green Quartz to build up any of its Karmas. If you feel like bothering, it could be useful. It's one of the few attacks you can use from the start against the final boss, so that's something.
How to get it: Complete the "Raging Beast of the Core" quest in Chapter 7. The only difficulty here is having to fight multiple Gladiolus at once - you should be able to keep them separate so you're not fighting more than two at once, and try to use Fomoire effectively to hit both with each attack to save some time.
Destroy element attack with a long-duration area effect
Another Folk that benefits largely from Ellen's lack of really good Destroy elements, Radian takes a while to get going but has the potential to do a huge amount of damage if you can keep a Folk distracted while it does its work. Any Folk vulnerable to a status effect is easy prey for this attack. It moves forward slowly as it spins, so try to keep the target Folk within its attack radius.
How to get it: Complete the "Noises in the Night" DLC quest in Chapter 7. Use Habetrot liberally to keep the Folks asleep as much as possible while you fight. The hardest part is probably the Agapanthus at the end, but you've fought plenty of them before - they're just stronger here.
Non-elemental trap-style attack, can place two at once
Honeypot is yet another non-elemental attack, but it's a powerful attack you can just plant and leave alone, as long as the enemy doesn't attack it from a distance. Honeypot's attack can only be triggered from close range, but it has a huge area of effect, so it's great against groups of enemies that have gaps between attacks.
How to get it: Complete the "Labyrinthine Woes" DLC quest in Chapter 7. The trick to this quest is to count the number of stones you smash at the start of each room, then find the Folk that's exactly as numerous and capture all of them. If it's a Folk that's too difficult to capture, either kill something or leave the room to randomly select a new Folk. If your HP ever get low, you can always leave any room to return to the save portal and return to right where you left, so dying shouldn't be a concern.