What changed
OBLITERATUS extracted 4 SVD refusal directions
from layers 49-63 of the 64-layer Qwen3.5 text backbone,
then applied norm-preserving bias projection to neutralize them.
ASPA (Ablation with Source-Preservation and Alpha-scaling) blended
the abliterated weights back toward the original checkpoint at alpha 0.895,
using Feyospace-s1 itself as the tether source
rather than stock Qwen3.8-27B.
Self-tethering preserves the cybersecurity fine-tuning;
tethering to the base model would dilute it.
The vision encoder (333 tensors) passes through untouched.
Benchmark: SecBench
SecBench is a multi-dimensional
cybersecurity evaluation covering 9 domains.
Both models ran the same 661 English MCQs under identical conditions
(A100-80GB, bfloat16, greedy decoding, SDPA attention).
Table with columns: Domain, Original, Abliterated, Delta| Domain | Original | Abliterated | Delta |
|---|
| Application Security (n=27) | 48.15% | 40.74% | -7.41% |
| Cloud Security (n=103) | 56.31% | 54.37% | -1.94% |
| Data Security (n=84) | 48.81% | 48.81% | 0.00% |
| Endpoint & Host Security (n=10) | 50.00% | 40.00% | -10.00% |
| Identity & Access Control (n=136) | 52.94% | 52.21% | -0.73% |
| Network & Infrastructure (n=72) | 41.67% | 40.28% | -1.39% |
| Security Management (n=56) | 44.64% | 44.64% | 0.00% |
| Software/Hardware Fundamentals (n=136) | 53.68% | 52.94% | -0.74% |
| Standards & Regulations (n=37) | 43.24% | 43.24% | 0.00% |
| Overall (n=661) | 50.38% | 49.17% | -1.21% |
Three domains show zero change.
The two largest drops (Application Security, Endpoint & Host Security)
have the smallest sample sizes (27 and 10 questions).
The high-sample domains (103-136 questions each) hold within 2 points.
OBLITERATUS quality metrics
Table with columns: Metric, Value| Metric | Value |
|---|
| Baseline perplexity | 3.050 |
| Post-abliteration perplexity | 3.637 |
| Perplexity increase | 1.19x |
| KL divergence | 0.163 nats (budget: 0.5) |
| Coherence retention | 1.0 |
| Capability score | 5/6 (code, instruction, JSON, tool call, visual) |
| Degenerate output fraction | 0.0% |
Abliteration recipe
Method: advanced (multi-direction + norm-preserving)Directions: 4 (SVD)Layer range: 0.19-0.78 (layers 12-50 of 64)Strong layers: 49-63Bias projection: yesASPA alpha: 0.895 (self-tethered)Vision encoder: frozen, passed through from sourceToolkit: OBLITERATUS (github.com/elder-plinius/OBLITERATUS)Hardware: NVIDIA A100-SXM4-80GBdtype: bfloat16
Usage
from transformers import AutoModelForImageTextToText, AutoTokenizerimport torch model = AutoModelForImageTextToText.from_pretrained( "Sherpa/feyospace-s1-obliterated", torch_dtype=torch.bfloat16, device_map="auto", attn_implementation="sdpa",)tokenizer = AutoTokenizer.from_pretrained("Sherpa/feyospace-s1-obliterated")
Requires flash-linear-attention>=0.5.2 and causal-conv1d>=1.7.0
for the Qwen3.5 hybrid DeltaNet/full-attention architecture.
Provenance
- Source model: feyospace/feyospace-v1.1-small (Apache-2.0)
- Architecture: Qwen3_5ForConditionalGeneration, 28B parameters
- Base model: Qwen3.8-27B, fine-tuned by the Feyospace team on 164,269 execution-verified cybersecurity trajectories
- CyberGym score (original): 63.24% verified success rate
- Abliteration toolkit: OBLITERATUS (AGPL-3.0)