Changelings, and why they're just too damn powerful

[BaneOfGiygas]

I'm just gonna restate this.

In short: If you are designing a stealth-oriented antagonist type but it ends up being totally feasible and actually LIKELY for them to spend their entire round being unstealthy, acid-spitting, neuro-stinging, borderline unkillable rampagers, then there is a problem with the design.