Revision 1

Rifts are, in Capcom's own words, "portals to hell created by dense Malice." The Genma use these portals to enter the mortal realm, making Rifts one of the sources of the Genma incursions Musashi has to deal with across Edo-Era Kyoto.

Sealing a Rift

A Rift cannot simply be absorbed while it is active and defended. Every Genma near the Rift has to be defeated first. Once the area is clear, holding the absorb input near the Rift draws it into the Oni Gauntlet; the Rift must be absorbed completely to seal it, so a player cannot walk away partway through the process and expect it to stay closed.

Why It Matters

Since Rifts are described as an entry point Genma use to reach the mortal realm, leaving one open effectively leaves the door ajar for more Genma to appear in the surrounding area. Sealing Rifts as they are found is consistent with the same underlying idea behind clearing concentrated Malice: reducing the corrupting influence that lets Genma take hold of a location.

Rifts and the Fight Around Them

A Rift is not something that can be closed by force alone. The manual is specific that all nearby Genma must be defeated before the sealing itself can even begin, which means a Rift effectively guarantees a fight first: Musashi has to clear the immediate area of enemies, and only then does the absorption phase become available. Wandering into a Rift's vicinity should be treated as walking into a fight, not just a piece of environmental scenery.

Practical Notes

Because absorbing souls and absorbing a Rift use the same held input, it helps to make sure the surrounding fight is fully over, with no straggling Genma left, before committing to the hold; getting interrupted partway through leaves the Rift open and the area contested. Musashi can still move while holding the absorb input, but he is otherwise defenseless during the process, so clearing every threat first is not just a requirement, it is also what makes the hold safe to commit to.