Model not mine, all credit goes to Rule34Diffussion:

https://civitai.com/models/1442808/helltaker-style-illustrious

Starting Prompt: (Quality & Style Prompts)

masterpiece, best quality, amazing quality, flat_color, sharp, (2d, cartoon, toon \(style\):1.2), (shiny, bloom, glossy, vibrant, edge lighting, volumetric lighting, rim lighting),

Style Prompt/Lora Model Weight: 0.7 - 0.8 works well

Tigger word: helltaker_style

[Your own prompts here].

I use character prompts so they are at the bottom, and any actions, outfits, or backgrounds are placed in the middle.