Here’s a cheat sheet of all Inazuma craftable weapons and their synergies with all current playable characters.
Great means that weapon works well with the character, and it’s one of their best 4-star weapon options. Decent means that it works on the character, but there are other far better options (usually other 4-star gacha weapons). Not recommended means that it doesn’t synergize well with the character – or there are significantly better options (usually other craftable weapons or 3-star weapons).
Amenoma Kageuchi
Amenoma Kageuchi is easily the best weapon of this series. It has a really good passive that’s easy to proc and grants a lot of energy, especially with refinements. At R5 with 3 Succession Seeds, Amenoma effectively regenerates 36 energy to its wielder. This extra energy significantly decreases a unit’s energy requirements, thus letting you focus on more damaging stats instead. So it’s a great weapon option for every ATK-scaling character that often casts their skill and burst. Amenoma is only unfavorable for units that need more Energy Recharge (like Xingqiu), don’t scale from ATK (like Albedo), or need a weapon with a higher Base ATK (like Bennett).
Hakushin Ring
Hakushin Ring’s passive only works for teams with an Electro teammate, so it’s a conditionally good weapon. It’s best used in teams that consistently trigger Electro-related reactions – and when the units triggering those reactions deal a significant portion of the team DPS. For instance, Hakushin Ring is great in Taser (Electro-charged) teams. Its passive effectively buffs Hydro and Electro whenever Electro-charged is triggered. So although the Hydro unit wielding Hakushin (usually Kokomi/Barbara) doesn’t deal a lot of damage, they do buff Fischl and Beidou – aka the two most common Taser party members. And these two deal most of the team’s overall damage. Additionally, Hakushin’s passive doesn’t trigger off-field. So its wielder should often stay on-field to maintain buff uptime. This is the reason why it’s less favorable on units that mostly stay off-field – like Yae Miko. And in teams without an Electro unit, Hakushin is just an Energy Recharge (ER) stat stick with a high Base ATK. In this scenario, other catalysts are simply better.
Hamayumi
Hamayumi is a great option for every ATK-scaling DPS bow user who mainly deals damage with their normal/charged attacks. This is thanks to the first part of its passive. Its effect is an unconditional damage gain to any character that performs normal or charged attacks. However, the second part of its passive is less consistent. Casting a character’s burst is very often recommended – it’s simply additional damage. So it’s harder to maintain 100% energy on a character. Melt Ganyu is currently the only character that can fully benefit from Hamayumi’s passive. This is because Melt Ganyu doesn’t cast her burst at all, so she can easily maintain 100% energy – assuming she’s not using a 4pc. Shimenawa’s Reminiscence (4SR) artifact set since this set drains the wielder’s energy.
Katsuragikiri Nagamasa
Katsuragikiri Nagamasa is a good weapon, but it has a lot of competition. It has a good base ATK, high Energy Recharge (ER) stat, and an overall nice passive. However, there isn’t a single claymore user that can fully benefit from all of these. And in most cases, other 4-star claymores are simply more favorable. This is because of Katsuragikiri’s gameplay issues – which really just means that you have to work around its energy drain. And this can be frustrating when triggered at the wrong time. For instance, if you need a bit more energy to charge Beidou’s burst, casting her skill is the best way to get it. But with Katsuragikiri, you have to wait for the energy drain and regeneration before getting the energy you need – its energy generation passive isn’t instant. So it’s more comfortable to just go with weapons that don’t have gameplay issues like Katsuragikiri – plus other weapons are often just better in performance.
Kitain Cross Spear
Kitain Cross Spear is in the same spot as Katsuragikiri Nagamasa. It’s a good weapon, but there are plenty of other good 4-star polearms – all of which are a lot more consistent and don’t have any gameplay issues. For instance, Dragon’s Bane is easily the better weapon option for characters that want Elemental Mastery. And Favonius Lance is the best option for characters that want Energy Recharge. Kitain is a viable replacement for these weapons, but the difference is still significant. It’s always optimal to use the better weapon if you have them available – there’s no reason to use Kitain.