Revenge of Carnage (Merciless) is the second stage in River Acheron. When clearing this stage, the player is guaranteed to unlock the True Form of Express Cat, Bullet Train Cat. This is a No Continues stage.
- 2 Znaches spawn after 3.33 seconds100f, delay 3.33~5 seconds100f~150f.
- 4 Ginger Snaches spawn after 6.67 seconds200f, delay 6.67~8 seconds200f~240f.
- When the base reaches 99% HP:
- 8 Ginger Snaches spawn after 0 seconds0f, delay 30~40 seconds900f~1,200f.
- Infinite Zrocos spawn after 0 seconds0f, delay 30~40 seconds900f~1,200f.
- Infinite Znaches spawn after 0 seconds0f, delay 30~40 seconds900f~1,200f.
- 4 Zir Zeals spawn after 0 seconds0f, delay 60 seconds1,800f.
- 6 Zigges spawn after 0 seconds0f, delay 33.33~50 seconds1,000f~1,500f.
- 1 Hannya spawns as the boss after 0 seconds0f.
The map is noticeably shorter than the original stage Hannya appears in, Realm of Carnage. This characteristic exacerbates any mistakes related to the burrowing patterns of Zombies.
Also, if you have a tanky Uber Rare like Cat Machine Mk 3, you can use it to stall Hannya to prevent it from attacking your other units while protecting your base from the Zombies since they burrow earlier.
Strategy 1 (Uberless)
Only use cats in row 2, who must ideally be level 30~40. Zamboney can be replaced by a good anti-zombie uber or something to damage Hannya while no-one is in front of it.
It's also possible without Housewife, if you want to do it no gacha for some reason, but she still makes thing faster by sometimes killing zombies in place of Islands, so she's worth having.
Battle: start with a single Manic Island (level used was 40 but higher is recommended), then upgrade the worker to level 2 or 3; after that, start spamming Manic Island and Zamboney and never stop for the rest of the fight.
Once Hannya appears, the real battle starts. From now on, spam the other units based on the following: Island Cat only when you have a lot of money, Li'l Flying when a zombie wave appears and Housewife shortly after you start with Li'l Flying. You should always end up with a group of Islands keeping Hannya at bay while another army that includes the 2 zombie killers takes care of the zombies, with the eventual help of the cannon.
It shouldn't take a lot; with all those combos, your strong units will decimate the stage, despite no items or ubers being used.
Strategy 2 (Uberless)
Cat Cannon: Breakerblast Cannon
Battle Items: Rich Cat (required)
Manic Island, Island, Doctor, Wrestling and Fishman are a part of their combos
Battle: When starting the match wait for the Ginger Snaches to come near the base and stall with Roes and anything you need to keep them at bay, but try not to kill them yet. Once the Znaches arrive, send out both Islands. After Znaches and Gingers are dead spam Manic Island, Roe, Can Can, and Seafarer, making sure not to stop spamming those 4 units.
Use Maglev for damage control on the Zeal and Zigges; focus the Zeal first. A. Bahamut can also be used for damage control and even damage towards Hannya if timed correctly. Hopefully, you will win.