I really don't think there is any reliable way past this one without Ravenous Prideling's combination of Elemental, Disruption and Life Exchange. I was left without my Prideling on the PTR (don't ask!), and tried all sorts of weird ideas, but only succeeded once with a Ruby Droplet and some RNG. (edited)
You don't need the prideling to beat it, but without it the fight is such a huge RNG fest that you can't create a somewhat reliable strat without dispersion. I like that there finally is a reason to use this pet, but I think there shouldn't be a necessity to use it.... It's just that terrible rng (edited)
Yes, that's my point. And reliability is a requirement when doing a scenario where you can't heal. It's a fairly standard dev move to require you to use a particular mechanic, as they do regularly with the Boss buff to force us to use a Bleed and Stampede approach. Requiring an approach is one thing; requiring a specific pet for reliability is maybe a step too far.
Unless, of course, we've all missed something ... (edited)