Since I awakened my first Kelsus I just got enough for the second today and headed to the dummy to test jump chaining with the full group.

So the upside: the Missile Shelters and the Ignito blasts from an enhanced Crimson Death all perfectly spark chain with each other every single time. The downside: the actual jump damage, what you'd want to chain, does not.

This is what you get ~80% of the time, a 23 spark chain with jumps that independently 1-chain with each other.

If you don't enhance the Crimson Death jump beforehand, it's not any better. Most of the time it's a 9 chain from the Missile Shelters and jumps that don't do diddly squat.

On very rare occasions you get one of the jumps in there, resulting in a 24 chain from the first bit of damage but nothing remarkable afterward.

I did between 1 and 2 dozen tests per combination of enhanced and non-enhanced Crimson Death jumps, tested different timing for activating units (including just pressing Auto), and could find no pattern at all for getting a consistent result with getting any of the jumps to chain.

I know that JP Arenea chain vid is floating about, but I don't know if her jump has more consistent damage timing or what.