P5S Reaper Boss Fight (Merciless, Solo, No Omnipotent Orb, Not Depending on Technical Damages)
I did not have access to a good screen recording software, so this was recorded using my iPad, camera pointing towards my laptop screen. There's also no audio in the original recording. BGM was later added to make the video slightly more enjoyable. Sorry for the low quality.
I consider this a proof-of-concept video. Every video I could find on soloing the Reaper fight on Merciless uses either the Omnipotent Orb (which makes the fight just boring. Apart from Reaper's Megidolaon, nothing can even cause any damage. Using Omnipotent Orb, I even finished a solo Reaper fight using no item. It's just long. Took me about 30 mins.) Or it depends on Technical damages. The popular method seems to be inflicting Dizzy on Reaper, then spamming Morning Star ( • Persona 5 Strikers : Joker vs Reaper (Merc... ). Though I also found videos inflicting Freeze on Reaper then using Physical/Gun attacks ( • Arsène Solo vs Merciless Reaper [Persona 5... ). So this is more of a challenge fight to see if that's truly necessary.
During the fight, no ailment inflicting skills were used. All my Fire/Electricity/Ice spells were on Lucifer, which didn't have any ailment boosting or elemental boosting skills on it. And I never attacked with the intention of inflicting ailments on Reaper. (Dire Shadows summoned by Reaper were fair game, though even those were more by-products of hitting their weaknesses.) At about 37:09, Reaper was shocked and I hit him with a few Cosmic Flare. They didn't cause much damage and that was the only time any Technical attack hit Reaper. (I honestly didn't expect Reaper to be shocked. I was actually just trying to hit the Dire Shadow.) So, all in all, this is sort of a brute force approach to the fight. (The Personas used weren't even specifically tailored for the fight. I just brought in my usual slate of Personas, didn't change any skill. The only exception was Yoshitsune which I put an Endure on, which actually didn't trigger anyway.)
I actually hope this gives an indication that it might be possible to solo merciless Reaper without using any item. I used lots of items in my fight, but following a similar approach with different Persona builds, it should have been possible. Instead of making Yoshitsune Null/Drain all elements, one should instead do it to Lucifer. With Shadow of Grief, it should be possible to recover lots of SP. One could also use skills and drain attacks to recover HP instead of using items. The times I used items to increase my Showtime gauge were honestly unnecessary. I just got scared of Megidolaon, but one could just dodge it. (I did that in my with Omnipotent Orb but without item run.) So, yeah, that should be possible. But I'm not going to do it. Not depending on Technical attacks is already hard enough for me, so I'll leave this challenge to those who are better at this than me.