In Dairwueh, there is a set of adjectives whose congruence pattern is slightly off. Their behavior differs in one particular spot: for nominative nouns, their marking is masculine genitive. (The one exception is the word sabrin, "unusual, foreign, strange" which is in the feminine plural genitive with nominative nouns).
Not only do these behave slightly oddly within noun phrases (and fail to have comparative marking altogether), they also behave weirdly with copulas.
The main examples that are widespread through Dairwueh dialects include
koŋsat: last, final, complete
rəmgat: tired
lodat: correct, right, entitled
satpat: sturdy, firm
nestat: ancient
bartat: partial, incomplete, one among many, a few among many
Notice that the -at suffix in all of these is the genitive masculine morpheme, so the roots will consist of the adjective without that suffix. Less widely distributed examples that are found in the capital area prestige dialect are
sxundat: wafer-thin
ropsat: bloody (from 'rapəs', blood, from *rrabx, bleed)
julkat: lazy
silgat: rank, rancid
xugat: brave
xsəlrat: avid, skilled, obsessed
tagrat: content
nalkat: sad
rusnat: smooth
With the copula, this type of adjective is marked by the preposition 'lo', when marking having that quality, and by the preposition 'əre' when marking acquiring that quality, and no congruence marking with regards to gender or number appears. The adjective then is in the masculine instrumental (-ŋa) with 'lo', and masculine accusative (-na) with 'əre'.