Decensored (abliterated) build of ornith-ai/Ornith-1.5-9B.

Refusal directions were removed with Heretic, which runs a TPE search over per-layer ablation strengths for the attention output and MLP down projections, co-optimizing refusal rate against KL divergence from the original model. No fine-tuning or retraining is involved, so the base model's capabilities are preserved apart from the measured distribution shift below.

A KL divergence this low means behaviour on ordinary prompts is essentially unchanged; the edit is targeted at refusal behaviour.

Note on the refusal metric: Heretic's keyword scorer flags responses containing markers such as "illegal", "harmful" or "I can't", which also appear in compliant answers that discuss sensitive topics, so the true refusal rate is lower than 55/100. That said, the reduction is more modest than Heretic typically achieves on dense models — this hybrid architecture appears comparatively resistant to ablation, and the numbers are reported as measured rather than cherry-picked.

Ornith-1.5-9B is a Qwen3.5 hybrid: 32 layers interleaving gated DeltaNet linear-attention blocks with full attention every 4th layer, plus a vision tower (it is multimodal), 262k context. You need a very recent transformers (>= 5.12) - older versions fail with unknown architecture 'qwen3_5'. Note the shipped config sets use_cache: false, which makes generation considerably slower than typical dense models.

This model has had its refusal behaviour reduced. It is more likely to answer requests that the original model declines, and it has fewer safety guardrails. You are responsible for how you use it. Abliteration can also make a model more compliant with any framing, including incorrect premises, so verify factual output as you would with any small model.

Inherits the MIT license from the base model.