[EenKogNeeto]

When using certain on-hit weapons, and most on-crit weapons in your offhand, your main-hand weapon can apply the effect as if it were that weapon. Example being: Atlatuas Abaniko applying silence, Guitar doing AOE sound damage, so on and so forth.
This is mostly an issue in two cases of increasing severity: When using handguns (As you get to proc it multiple times when it probably was based around only happening once), and leadstorm (As you get to proc it multiple times on multiple people)

The main reason I see this as an issue instead of a fun mechanical thing is...Using a guitar offhand and a quickdraw mainhand, you can fly into the enemy team and do two hundred damage to all of them assuming a single member of their team hasn't stacked crit evade high enough to resist you. And this multiplies by the number of people not immune to crits on a given team potentially leading to an instance where a single person can instantly kill a four-person party, despite not being able to win against any of them on an individual level.

What should happen: Only applicable if you actually hit them with that weapon, same as MLM being changed to only give its crit damage to itself.

I would be lying if I didn't explicitly give some people the idea to use this knowing it would probably need to be fixed, and the reason it's here rather than bug reports is... It's working as intended, so a balance fu was required instead.

Other noteworthy fun uses are using a jackhammer to silence the entire enemy team at the start of combat even without leadstorm, Using two guitars to shred super hard when you do the special attack with an axe while surrounded, and so on and so forth.

Sorry dark bard, but six hundred total damage with only one person on a three man team getting hit is a biiiiit much.

PS: And all this doesn't even begin to describe how effective it is in PVE.

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Rather than edit and restructure this post I'll leave it for the sake of other peoples arguments having context.

This edit is because I have done further testing and found that Abaniko and other on crit weapons do not interact the same way with a mainhand weapon. It's ONLY the guitar that works this way that i've found after testing everything from Anchor Edge to Tarnada to Abaniko. Which I feel makes it quite obviously something that should be changed to bring it in line with every other weapon.

TESTED AND DOES NOT PROC ON MAINHAND
Anchor Edge: On Critical: Inflict Immobilize for 2 Rounds.
Skullcaver: On Critical: UL/2% chance to inflict Stun.
Thornshooter: On Critical: Immobilizes the target for 2 Rounds.
Abaniko: On Critical: UL% chance of inflicting Silence for 2 Rounds.
HOTG: On Critical: UL% chance to inflict Knockdown for 2 rounds.
MLM: On Crit: If target is Feared and is a non-boss Monster, they are instantly killed.
Ryeser: On Critical: Reduces the target's Momentum by 1 if they do not resist Lightning damage, to a minimum of 3 Momentum.
Tarnada: On Critical: UL% chance of casting Vydel, for free.

PROCS ON MAINHAND:
FULLY - Guitar: On Critical: Inflicts unresistable Sound damage to all enemies in 5 Range equal to this weapon's Power.
SOMETIMES - Deadly Smile* (Tested by Lolzytripd): On Critical: If target is feared, inflict Knockdown.

*Only works in certain situations apparently

The others were untested because they tend to be fairly unused and you get the picture by now. Feel free to grab stuff like an Abberation spear and check yourself.