Bore is a spell that allows the caster to open a vent to the underworld. It has only been used by Kofuku while using Daikoku (Kokki) as her medium.
Bore (like Rend) is actually an anime-exclusive spell, having not been in the original manga version, in which Kofuku does not chant the spell.
This spell causes a vent to open, which will also cause a Phantom Storm, due to Kofuku's "bad luck". Phantom Storms are very dangerous, which is why Kofuku avoids using Kokku unless she considers the situation dire. Often, Daikoku shows resistance to being used for this spell.
Kofuku, opening a Vent in Revival.
The first time Kofuku uses her ability, in Scary Person.
Casting Sequence
O band of fiends treading upon sacred land! With the [Kokki], I pierce you! Bore!
(Most common translation.)
Kofuku uses this casting sequence in Revival, when opening a Vent for Bishamonten to go rescue Yato in the Underworld. However, this casting sequence was not used the first time this ability was shown, in Scary Person.
This casting sequence is very similar to Rend, which is used by Yato frequently in the series.
Known Users
So far, only Kofuku has used the spell with her shinki, Daikoku. It is possible the spell can only be used by her, since it is a cause of bad luck, which is highly attributed to the God of Poverty.