Like, i get it's a chaining but everything like it has been mediocre and the rad procs doing extra hits is cool and may help it but it's gonna be helminth fodder if just for the extended animation lock alone.
So instead i suggest the wind up lead to the chest opening/closing really quickly so it creates a huge 95 degree flash that does a lot of damage in one hit, directional nuking that stacks with rad procs the same way, add blind or nauseous crawler stun or eventual aug for lasting radiation area and boom it's way better.
Think like a nuclear camera, it's even named 'blast' so give it some PUNCH, being only directional LoS nuke would let it stand out and be better then a lot of the other big wide 4 nukes in raw damage and support options. (it could also be a high drain elongated blast as it is now too)
Yesyes i know, 'you havent tried it yet' and 'it isnt finished dude', but this is the BEST time to give feedback to a core idea instead of numbers based, before they actually finish it and you wait potentially years for the rework.
This but in an instant or over half a second, whatever blend of balance/flair you like because warframes by design are a power fantasy of some kind: