Board Thread:General Discussion/@comment-2601:84:C604:FD80:9050:ABDB:6CCC:904A-20171231024101/@comment-2607:FEA8:4E20:711:3061:1B1B:DF63:959-20180116122821

Now that the increased drop rate for rare swords at the boss node campaign has begun, why don't you try to grind for Kogitsunemaru in either 5-3 or 6-1 instead? Hopefully that should make it easier to get him if you keep trying at either of the maps. Taikogane can also be grinded for at 7-2 easily enough with a full kiwame tantou team (or five tantous plus one Lv. 90+ yari if you want to deal with those annoying 1 HP enemies better, although they rarely appear for the most part, so six kiwame tantous will generally be more efficient to use).

It would probably be better to use the seals for an event sword you don't have, if you can, considering how hard it is to get them normally (like Ookanehira, in fact, since you were unable to get him in the Regiment Battle).