Hanzo shits via hype but he has no feats so...
Resisting ET naturally is a feat.
Being senile and still managing to overpower the world's greatest Kenjutsu user with nothing but a sickle is a feat.
Defeating Proto-Team Hiruzen is a feat even if we never got to see how.
Don´t forget that Jiraiya (based on his knowledge) didn´t believe anyone alone could beat Hanzo. Ok I am not going to say this include characters like Itachi,Kisame or others he had little knowledge but he certainly had full knowledge on his own capabilites and probably full knowledge about Orochimaru,Hiruzen and Tsunade capabilities. Even if he didn´t have full knowledge about Oro/Hiruzen/Tsunade we know that SM Jiraiya would beat any of those 3 .
Hanzo's feats are ambiguous and incalculable since we're shown how powerful the Young Sannin are and majority of Hanzo's feats were explicitly illustrated when he grew complacent and was ill-involved in battle which would lead to spurious conclusions. Portrayal is likely the most effective avenue towards evaluating Hanzo's combat ability such as Jiraiya's reverence for Hanzo's power or Hanzo's ability to manage an small, isolated nation even when pitted against all of the five renowned shinobi villages.
We likely haven't even witnessed what Hanzo's capable of and it's plausible that Hanzo can use explosive tags as a means to obscure Sasuke's Sharingan and create an opening to release Ibuse's fumes.