Hell Oni doesn't have its own category in the Ranking Criteria and is treated the same as Inner Oni there, just like Extreme in osu!standard for example.
The existence of Hell Oni in the default difficulty naming can cause confusions where certain mappers mistreat inner and hell oni as two separate entities and cause the following argument: "this difficulty is hell oni therefore you need an inner as the diff below it" which is plain wrong.
This has occurred many times in the past, and such example can be seen here
To add to that, there isn't a gamemode other than taiko that has an official name for black icons, which doesn't make a lot of sense in terms of consistency as you can see here:
Also, Hell Oni isn't even very common nowadays mainly because people tend to prefer to use custom diff names.
I propose to remove "Hell Oni" from default difficulty naming, and put it in "Widely accepted alternatives" with the following description:
"it can be used to represent a more difficult Inner Oni."
The existence of Hell Oni in the default difficulty naming can cause confusions where certain mappers mistreat inner and hell oni as two separate entities and cause the following argument: "this difficulty is hell oni therefore you need an inner as the diff below it" which is plain wrong.
This has occurred many times in the past, and such example can be seen here
To add to that, there isn't a gamemode other than taiko that has an official name for black icons, which doesn't make a lot of sense in terms of consistency as you can see here:
Also, Hell Oni isn't even very common nowadays mainly because people tend to prefer to use custom diff names.
I propose to remove "Hell Oni" from default difficulty naming, and put it in "Widely accepted alternatives" with the following description:
"it can be used to represent a more difficult Inner Oni."