
Gonna start off by saying tether application from side b / aerial down b is completely fine.
My entire issue is with neutral b. Neutral b gives Maypul a non-commital, easy to land projectile which immediately gives her her win condition. She can just play back, run away with the fastest run speed in the game and continually throw these out to force approaches and gain her win condition.
You only can then remove mark by grabbing her, which is situational and also makes intent incredibly clear unless you get the hit already, or by parrying her. This is meant to be made easier by Lily being parryable but the Maypul can just choose to not plant Lily while mark is active, forcing you to play with this massive downside which can let her kill you nearly at any time.
There’s a few solutions to this, either to making neutral b more committal/require more thought, or making Mark easier to remove.
On the first option, you can either make neutral v harder to land through slower startup or travel time/distance, or, what I think is better, is to give it a cooldown, say about 3 seconds. It prevents Maypul from just spamming it at you while you try to close distance to prevent her from doing that as she has to reposition between each neutral b attempt.
Making mark easier to remove has options too, whether that being her taking damage at all removing it (probably not) or it being on a timer, for example after 10 seconds, mark gets removed. If you don’t want to adjust neutral b, I think this is the best option, although it absolutely hurts side b / air down b which are actually harder to connect with.
There’s also the out there change which is addressing the main elephant-in-the-room move about tether which is fair. I again don’t think this is the best bet in fixing the mark issue but I think it’s still important to list it. Fair’s diabolical angle is the main reason tether is despised. Getting sent that far at that angle can kill certain characters incredibly early with tether confirms making it incredibly easy. Adjustments to fair such as launch angle, knockback or speed would make this a bit more tolerable and not feel as ruthless to be hit by if we don’t want to adjust the tether mechanic itself.

I’d be fine with a seed cooldown