I find it amusing how everyone says that. And yet:You know, Yamaraja has combo- too. And having a back-up B debuff is not a bad thing at all.
Add in her debuff prevention which allows you to avoid Ares' fire should you need to (or Acala's def- if you use her), her elem+, her huge nuke which can be used outside of Rage phases too... Yamaraja is quite solid. Not somebody you should get with a Miracle ticket, but shouldn't be overlooked if you happen to get her.