Use Obariyon's Lucky Punch, Morgana's Slingshot, and Ann's Gun. You can restart this fight if you die so take some chances in the beginning to do a lot of damage instead of guarding. Save before you play around so you don't waste money.Norn(L52) is a great caster for exploiting weaknesses, has no weaknesses of his own, and comes with a pretty good magic stat. The big guy is susceptible to sleep so go for tech hits.Not the final PoNR in the game, but an important one. This does not mean you must redo what you've already done.
Put Ryuji, Ann, and Morgana in your party before the fight, Haru should replace Ryuji.
Make sure you cure brainwash immediately.
He also comes with Lucky Punch which can knock down Archangel for a measly 5 HP cost. If it's not the one you're looking for, you can escape the battle, engage another enemy, escape that battle, and the treasure demon will reappear for you to try again. This is a non-elemental multi-hit attack that will kill anyone who isn't guarding. Also make sure you have some kind of supply of healing items. If you follow one simple rule, you should be able to navigate through all rooms and collect all treasures with minimal backtracking. This also means you're immune to Burn, Freeze, and Shock. Pay attention to how enthusiastic your teammates are about the items they propose throwing and it should be obvious which item will work. It's very useful. Even random encounters can be rough.This guy packs a lot of power. Luckily you have the 3 best casters on your team and you should have Norn to do your share of damage. )You'll see him as Uriel because you've fused him before. The latter are on defense with Marakukaja, Matarunda, and healing. I managed to kill him at L6 with some luck and even had enough SP to reach the palace treasure. Lastly, he takes reduced damage from physical attacks which is very useful in the upcoming palace boss fight.After exhausting all of your SP, head back to the real world and upgrade your melee weapons before coming back for a second day. You should probably save the money farming bit until after you secure the treasure though. Ann can heal during this phase since her fire won't hit very hard, but don't neglect Tarunda. Equip Joker with a persona that resists wind, and leave Ryuji out of the party. Also, never watch DVDs. His moveset is mostly bless/curse so make sure you aren't weak to either.
Yusuke will automatically be in this fight and should be able to wipe out the 4 weaker enemies with Bufu as long as he doesn't miss. Okumura was a cakewalk on MercilessYeah, he's much harder to beat on Hard because you're in that inconvenient place where enemies are tougher but you don't get the damage bonus for hitting weaknesses, and the whole fight is about that.Favorite 3H characters: Claude, Hilda, Dorothea, Sylvain, LinhardtThey tried to claim Merciless as hardest difficulty. Inherit Null Bless and you will be near invincible.Corporobo MDL-? Due to the severely reduced XP, you'll probably only be around level 54 unless you did some serious grinding. For Persona 5 Royal on the PlayStation 4, a GameFAQs message board topic titled "Merciless is too easy? "Discover the items and services Jose's shop provides in Mementos!" No enemies at all, but there are a couple treasures you can grab.Secure the infiltration route. Bring Ryuji, Ann, and Makoto to the boss fight with the strongest armor you can buy.Note: You will have to discuss the calling card at the hideout after securing the infiltration route in order to rank up your teammate confidants. Ann will need hers for Tarunda and Morgana will need his for Media during the boss fight. If he uses Concentrate, switch to a Null Elec persona after he wastes a turn glaring at you.After activating the bridge you should have over 10k coins leftover, which is more than enough to purchase all prizes on both floors. Take the safe bet when prompted, color won't matter. Lastly you need a Kelpie(L6) for Tarunda to keep the mini-boss from one-shotting your party.Hopefully you have plenty of SP. You'll have to fight the paintings two more times but they'll have less health each time. Just like the last boss, take out the small robots quickly or you're gonna have a bad time. Brave Blade has a decent crit chance and Negative Pile can inflict Despair so cure that immediately. Memorize your party's turn order.The most important thing is to make sure The Reaper does not get a turn when only Joker is alive. Yusuke should do the same thing with his strongest ice spell.