There are biological differences between certain pain perception receptors in birds and mammals. The TRPV1 (transient receptor potential vanilloid subfamily, member 1) receptor, also known as the capsaicin receptor, is involved in the perception of unpleasant or harmful chemical,

physical, and thermal stimuli. The molecular sequence of this receptor between birds and mammals is only 68% similar, as compared to the >95% similarity for most other central nervous system receptors. What this translates to is an unusually high avian threshold for tolerating

the spice in hot peppers. While mammals are put off by concentrations of 10-100 ppm (up to about the heat level of a jalapeño pepper), birds are not even fazed by capsaicin levels >20,000 ppm (habanero pepper territory).

Lucifer king of being completely unfazed by diehard spice challenges. This does not apply to Sandalphon because he should suffer.