Idea: Gembrain-X-Core is a ground-up rebuild of Gembrain-31B, thought to be a true successor with the spirit of the original. It was a pretty time-consuming task, as just re-merging it to preserve some smarts didn't really cut it. The idea was to actually improve the overall strengths and weaknesses I've gathered about it online. While the original Gembrain-31B lost some of it's non-refusing and engaging spirit that Gemsicle once brought with it, Gembrain-X-Core shouldn't have any of that. Even if it is a rough goal to achieve, I'd say now it acts equally creative as it is smart, context-aware and prompt-adherent.

Creative RP: Its mix of adherence and swipe variety is the standout for me. Hand it an open-ended turn, ask for fresh scenes or scenarios, or have it twist a situation, and it comes at the same context from genuinely different angles more often than not, not re-running the same idea over and over again. Random characters it invents for image prompts are just as varied. For roleplay purposes it holds up what is thrown in: characters pursue their own agenda, and pace the scene rather than caving to the user, and with thinking on and a good character description in front of it, the portrayal sharpens into something that is evidently more true to the core of the character's description.

Colorful Mix: Gembrain-X-Core rolls with whatever the scenario is and uses the language register the way the moment demands. It can stay classy, but it has no personal business reaching for euphemisms. While this merge obviously can't run away from it's own heritage, and the initial Gemma 4 31B IT baseline is generally very user-adherent and very horny, Gembrain-X-Core won't try to fight it. Instead, I decided to go with the flow and add some fine-tunes that were trained to genuinely pace through and believably portray these specific scenes; turning explicit content into more vivid descriptions, not into the guess-work of the eager but clueless base.

Image Prompt Generation: And that same descriptive precision feeds its image-prompt work: in my testing, it follows a prompt structure you hand it nicely, and writes clean and vivid descriptions of characters or scenery within the prompt. It produces several distinct image prompts in a single response without losing coherence, in my tests three at a time, several times without losing the format or anything - and thinking is not even required for that most of the time.

Fast or Deep: Gembrain-X-Core turned out to be a model with not just one, but two faces. In non-thinking mode it's a fast and versatile generalist: a reliable companion for ordinary questions, for roleplays with creative quirks, a partner to have conversations or quick chats with, and of course a creative and reliable engine for fast and structured image-prompt generation. But switching thinking on locks the model more onto the roleplay scenario or character, strictly adhering to the card's defining traits, which means neglecting some of the variety for overall coherence where it makes sense. It's reasoning can be verbose, but it really seems to improve the output with its genuine "No, wait"- and "Let's refine"-moments. Reading the reasoning is as a blend of Gemini-style and Claude-style thinking with a slight lean toward the Claude side across most rerolls.

Prompt Sensitive: The merge is nicely steerable in it's output length and even adjusts verbosity to the given system prompt itself; I noticed it going for a more verbose narration when using system prompts that frame the conversation toward roleplay (like Geechan's), and closing in to shorter-to-medium responses when using character-centered system instructions, clearly being able to make a distinction between both conversational styles. Ultimately, it adjusts to the demand of the scene and acts on it.