Zalgo text generator

The marks are real Unicode combining characters (U+0300 upward, U+0316 downward, overlays through, plus the small combining extension blocks), so the output pastes anywhere Unicode is accepted. That is also the limit: some apps and many screen readers render stacked marks badly or skip them, so the result can look plain, break the layout, or read as nonsense out loud. Newlines and tabs are left alone so paragraph shape survives.