SP Builds will be posted in the comments later. To be honest, not much changes.

Ensa-Taya

First, I'll look at Ensa-Taya. Gumi gave Ensa-Taya an animation that has a perfect 3 multiple hit pattern. It's also almost perfectly timed to spark with Miku, enabling the following patterns:

Miku -> Ensa-Taya -> x -> x -> Ensa-Taya

This pattern will spark the first Ensa-Taya 23 times, and the second Ensa-Taya 24 times.

It is important to note, however, that only the second Ensa-Taya will receive Miku's crit buffs! You'll need to sphere her for crit chance (but you're probably using Miku as lead, so Blazing Fists, I guess?)

Thus if you only use one Ensa, it's recommended to do Miku > x > x > x > Ensa

To add in Allanon and still spark well, I unfortunately had to replace the first Ensa-Taya in the order. With a second Miku, you could theoretically create a separate spark track for that Ensa-Taya such as this:

Allanon (12 sparks) > Miku (24 sparks) > Ensa-Taya (23 sparks) > Miku (23 sparks) > Ensa-Taya (23 sparks) > Ensa-Taya (24 sparks)

Hopefully somebody can think of a second unit to perfect spark her against for those of us without two Sakura Miku, as I'm looking for a build that lets two Ensa get Allanon's element buffs, which needs a 2 unit gap between him and the first Ensa. Allanon's timing is such that you can't perfect spark him and two Ensa-Taya at the same time very easily without giving up element buffs on one of them.

For the record, the order Ensa -> x -> x -> Ensa will, demonstrable by the orders above, spark with each other, but only 20 times.

Ensa can also be used to perfect spark Azurai, if you want to use them together. Theoretical timings are Azurai > (Ensa) > X > X > (Ensa). I haven't been able to test it as all my Azurai friends are MIA in favour of Ensa already, so you may have to shift the Ensa positions by one unit (if you have to move them left it becomes impossible to perfect spark Azurai against 2 of her simultaneously). If you want to spark Allanon with either you may need to only use one Ensa-Taya.

In addition, Ensa-Taya's SBB DoT deals approximately 23.8k damage before DEF, and her UBB DoT deals 69360 base damage (both as lord type). If that'll make you consider it. Remember that DoT can't crit or spark, doesn't benefit from ATK buffs, but will deal more damage against a target weak to Ensa's base element (buffs aren't counted, increasing EWD does nothing for DoT)

Juno-Seto

Juno-Seto kept her 2 frame animation gaps. This means she sparks well with herself if you run dupes for some reason, will always get some sort of sparking off any spark blanket, but cannot receive a large amount of sparks from other units.

Most of the changes I'll be considering for Juno-Seto's builds are related to her newly revealed SP options.

The most important ones up for review:

• The BC cost reduction is 25%, which is nice. It brings the sphere requirement for 0BC cost down to 25% total, which opens up a few more sphere combinations, including just Elder Hat by itself.
  • I won't list out all the new combos. There's a bunch of spheres with 10% cost reduction that are fairly easy to get you can mix with the old 15% ones like Meirith and Four Bonds.
• Juno's REC->DEF convert is 60%. It's nice if you have no convert but do have a tri-stat buff around, however most units will benefit more from ATK->DEF due to ATK's prevalence in OE leader skills.
• Her BC/HC buff max value is 40%, not 35%. This actually makes it the strongest BC/HC drop rate buff in the game, and adds an extra 1-2% drop rate against heavily resistant enemies, which is still something (it'd be 8% drop rate total against 80% resistance, which you see in a few trial scenarios with multiple targets)