The summon guardian spirit feat allows the use of the summoning monster/nature's ally sorrel to call forth a more powerful version of an improved familiar.
All the major blessings for the alignments from the warpriest ability allows the character to call forth a single creature as if using a summon monster spell.
The question is, can these 2 items be combined? If I was a level 16 warpriest with an evil blessing with the summon feat in question, can I legally summon an imp that is upgraded to the level 7 summon monster spell?