Skill for generating CK3-native art assets using the Nano Banana (Gemini 2.5 Flash Image) MCP tool. Includes style guide, category prompt templates, and DDS conversion reference. Encodes learnings from first batch: no circular frames, no vector art, no text, dark backgrounds edge-to-edge, consistent orientation within trait families, max 3 parallel generation calls. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>