[Zefyris]

Besides, Fear and Konoha are pretty much top-tier already

Spoiler for volume 10 onward:

Those two are only top tier under special conditions (if they let free reign to their bloodlust), which are usually not met at all as they are trying to suppress it until it disappear. So while they have an awesome reputation because of how impressive are their past, in reality they struggle to fight as soon as a high tier appear and need to team up with allies to defeat them.
At best under normal circumstances, fear and Konoha are middle tier in their own verse, compared to some fighters like N'Izoyi, Kokoro, Hinai or the others Dragonians, they're weak.

although in actual fact, Fear is getting weaker in the sense that her choice of weapons is diminishing as she continues to seal them with Indulgence Disks).

Well, except for

Spoiler for volume 11 onward:

the dual use that she start using from the volume 11 onward

Also, as far as I've read (volume 14), Haruaki isn't the type to get stronger physically. That's not his role in the story, he isn't supposed to fight but to ensure that cursed tools' mind don't stray away from their initial resolution by supporting them mentally, providing them both a place and an atmosphere where they can get rid of their curse without falling again in the darkness.