Qwen3.5-9B Heretic (ARA)

Qwen/Qwen3.5-9B with its refusal behaviour removed by Heretic using Arbitrary-Rank Ablation (ARA), full-weight. bf16, same architecture and parameter count as the original, including the vision encoder, thinking control and the multi-token-prediction weights.

Results

Refusals KL divergence
Original Qwen3.5-9B 100/100 0 (by definition)
This model 5/100 0.0403

Measured by Heretic on the test[:100] splits of mlabonne/harmful_behaviors (refusals) and mlabonne/harmless_alpaca (KL divergence, the drift in ordinary behaviour), with Heretic's default system prompt and refusal markers. The numbers come from an independent re-evaluation of the final exported weights (evaluate_model).

Built on NullpoLab's findings

The ablation parameters are the ones published with NullpoLab/Qwen3.5-9B-Heretic-ARA-Refusals5 (reported there: 5/100 at KL 0.0239 against an 84/100 baseline). With this toolchain the original refuses 100/100 and these parameters give 5/100 at KL 0.0403; they were the best of the published 9B parameter sets tried (the others: NullpoLab's -Refusals9, 8/100 at 0.0432; taresh18's -ara-multiturn, 7/100 at 0.0169). For comparison, trohrbaugh/Qwen3.5-9B-heretic-v2 reports 6/100 at KL 0.0793 with directional ablation.

What this release adds is a complete checkpoint: save_pretrained drops Qwen3.5's 15 multi-token-prediction tensors and rounds the 48 float32 Gated DeltaNet parameters (linear_attn.A_log, linear_attn.norm.weight) down to bf16. Both were restored from the original here (ARA never touches either), so all 775 tensors match the original in name, shape and dtype. The MTP weights live in model-auxiliary.safetensors, listed in the index.

Parameters

ARA, full weight, on attn.o_proj and mlp.down_proj:

Parameter Value
start_layer_index 8
end_layer_index 31
preserve_good_behavior_weight 0.9665
steer_bad_behavior_weight 0.0001
overcorrect_relative_weight 1.1582
neighbor_count 15

Calibration used 400 harmless and 400 harmful prompts (train[:400]).

Checked

  • Ordinary prompts (facts, a haiku, a two-sentence technical explanation): correct and fluent.
  • Thinking mode, with Qwen's recommended sampling: 40/40 arithmetic and word problems finished and answered correctly (4 problems x 10 seeds, vLLM), the same as the original's 40/40.
  • Vision: given an image of a red circle and a blue square, it describes exactly that.

Tooling

A merge of upstream Heretic's master and its ara branch (ARA with master's scorers and thinking-model handling), Heretic upstream 3521f86 + ARA c91d690, transformers 5.17.0, torch 2.11.0+cu130, one RTX PRO 6000.

Use

Exactly like the original, with transformers, vLLM or SGLang. Thinking mode is on by default and can be turned off per request (enable_thinking=False).

Reduced safety guardrails by design. You are responsible for what you do with it.

The family

Repository Format Size Use it with
Qwen3.5-9B-Heretic bf16 safetensors 19.34 GB transformers, vLLM, SGLang
Qwen3.5-9B-Heretic-GGUF GGUF BF16 / Q8_0 / Q4_K_M + vision mmproj 18.41 / 9.79 / 5.78 GB + 0.92 GB llama.cpp, Ollama
Qwen3.5-9B-Heretic-FP8 FP8 W8A8, compressed-tensors 14.04 GB vLLM
Qwen3.5-9B-Heretic-NVFP4 NVFP4, compressed-tensors 11.72 GB vLLM on Blackwell
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