So basically, we need more way consuming fruits affect the way certain weapons act. In the anime/manga we have seen many users combine their DF abilities with their weapons, in the MMnM mod we already have Moria's Scissors taking shadows if we consumed the Kage Kage no Mi, umbrella and Kilo, flintlock and Bomu, paper and Mini, etc., but other ideas that come to my mind are:
Murakumogiri and Gura: So there's a percentage to produce a tremor attack with this weapon if Gura is consumed, like every 10-15 hits your next attack will have some Gura particles, the characteristic sound effect and gives your opponent a shaking screen effect, staggering them.
Kikoku and Ope: Ope should be able to do something like this with any sword, but I'm just giving some love to Kikoku. Basically if your hakiexp or doriki is higher than your opponents, then you can amputate a part of their body (being random which part you amputate and just doing it once per entity/player until they die or maybe a cooldown between amputations). The amputated part will act like the soul ability from Yomi, if you get close to it you can still get it back if you get close to it. If you lose your right arm you cannot hit players (except if you're a Black Leg user), grab items or place blocks; with losing your left hand you won't be able to put a secondary item. If you lose your head, your POV will get stuck in the place it fell, but you can still control your body to get it back. If you lose your legs (any of them) you'll get slowness and won't be able to jump (Black Leg users won't be able to attack is they were using their feet).
Ace's knife, pipe and Mera: This is simplier, Ace's knife and Pipe gets burn damage. That's it, like if they were enchanted with Fire Aspect, but it will apply more ticks like if it were Fire Aspect III or IV (240 and 320 ticks respectively).
Hook and Suna: Gives Dehydration effect for a short time everytime you hit your opponent.
Nonosama weapons being able to change between the Bo and the Trident anytime you want to, it doen't need to have and additional effect for me, that feature will be already good enough.
Idk, these are some ideas. The Ope one is kinda stupid ngl, but the other ones seem more plausible imo. 🤔