Battle Cats - Rashomon - Aku Reincarnation (Merciless)

Note: This stage unlocks after beating Mount Aku in Aku Realms and contains an Aku Altar, capping your unit levels at what they are in Aku Realms.
Introducing this stage’s boss, Sathankhamun VIII:
Sathankhamun VIII is an Aku variant of Hannya, acting more similarly to the original than Hannya’s other variant, Black Okame. Sathankhamun has 1,200,000 HP, 3 KBs, 34,000 damage, and 650 range Omnistrike extending from -200 to 800 range. Sathankhamun has a 100% chance to Slow units for 2 sec, which combined with his high damage and 4.3 sec attack rate makes it unlikely for units hit by him to hit back. Your best bets on damaging him are with extreme backliners such as Cyberpunk or by sending rushers such as Fishman and Maglev to chip away at his health. Rarely will you be able to deal significant damage to Sathankhamun, so maintaining space and weathering the storm is your only way to get an opportunity to take Sathankhamun down.
The stage begins by sending in Sathankhamun followed by a Nimoy Bore soon after. Try to stall Sathankhamun near the base as much as possible while getting chip damage in with Slime’s Wave. Lure Nimoy Bore to your base, then stack up attackers and Bahamut on it. Try to use Mr. to bait Sathankhamun’s attack so Bahamut and your stack of units can get in to do major damage to him. Aim to get 1 KB on him before he kills all your attackers.
After this, Chickful A will join Sathankhamun, soon followed by Mr. Puffington. Additionally, a constant stream of Cerberus Kids will come in, which will basically prevent any damage from reaching Chickful A if you don’t have Slime. Try to chip away at Chickful A as much as you can, using Rock whenever Slime procs a Wave or Sathankhamun attacks to prevent Mr. Puffington from taking too much space away from you. If Mr. Puffington ends up way ahead of the other enemies, use Bahamut to deal major damage to it and Chickful A before Puffington can cause too much trouble.
Once these 2 enemies are dead, you have a clean shot at Sathankhamun and you must kill him here before the next Nimoy Bore spawns. Luckily, there is a very long time between the previous wave of enemies and the next Nimoy Bore, so don’t worry too much about time. Just time units to get damage on Sathankhamun and he will go down. From there, the stage becomes much easier without the threat of Sathankhamun and any stragglers can easily be dealt with using Slime.
Unit Levels:
Manic Eraser - 38
Rock - 30
Can Can - 40 (Alien target)
Slime - 37
Fishman - 40
Maglev - 40
Bahamut - 40
Recommended Ubers:
Tankers, especially Wave attackers, Slow Immune, and Anti-Aku
Rushers
Anti-Angel nukers
This stage also has a 30% chance to drop Calligraphy Cat.
Calligraphy Cat (who evolves into Teamaster Cat) is an anti-Relic spammable single-target attacker with Strong vs Relic and immunities to Curse, Wave, and Surge. At level 30, Teamaster has 6460 HP, 1765 DPS, 330 range, 510 cost, and 8.53 sec cooldown. Teamaster’s stats are significantly weaker than other Anti-Relic options, especially its main competiton: Slapstick Cats. Slapsticks just have objectively better performance against Relic, so Teamaster should almost never be used outside of 4-star. However, its immunities to Wave and Surge do give Teamaster a niche as a spammable attacker. Against Waves, Teamaster can serve as a sort of meatshield for higher range Wave Immune attackers, always being in front of the crowd. However, the only non-uber Wave Immune that has more range than Teamaster is Musashi, so take this role with a grain of salt. Additionally, Mushroom Cat works significantly better as a spammable Wave Immune attacker. Teamaster’s main uses are against 3 specific enemies: Haniwanwan, Kappy Jr., and Masked Hermit. Of these, the only major enemy to counter with Teamaster is Masked Hermit since he is a Relic Wave enemy who is supported by a Surge peon in Sinner Snache. Other than this, Teamaster unfortunately finds himself in the dumpster, outclassed by Slapsticks and Mushroom. Hopefully his TF ends up being good.
Music Used:
The Scions’ Dance in Purgatory - Fire Emblem Echoes: Shadows of Valentia