While the four of them were advancing, Shaun also began devouring the flesh of the king-level creatures.
The king-level flesh, after cooking, indeed yielded permanent attribute increases, though not substantial for the king-level creatures themselves due to their already formidable baseline strength.
However, the significance was entirely different for the Lord-class entities, as even Tenth-rank Lords would experience significant improvements.
After Shaun and the mutant orange cat finished their consumption, there was enough flesh left for the four of them. The remaining king-level creature flesh was then devoured by the elite zombie legion, which had their strengths prioritized.
The king-level creature flesh provided a significant amount of evolution points. However, because they had activated two life-saving skills, the increases weren't as significant.