Unicode tricks and hacks, vertical text, Non spacing marks

Question

I ran into some vertical text that overflowed on a popular site which surprised me and thought it was some sort of code injection.

!̸̶͚͖͖̩̻̩̗͍̮̙̈͊͛̈͒̍̐ͣͩ̋ͨ̓̊̌̈̊́̚͝͠ͅ

When I select it its like one character .. when I hit backspace its like tens of characters.. what is going on?!

Here it is outside a code block.

!̸̶͚͖͖̩̻̩̗͍̮̙̈͊͛̈͒̍̐ͣͩ̋ͨ̓̊̌̈̊́̚͝͠ͅ

According to HTML entity encoder/decoder at https://mothereff.in/html-entities , it decodes to this:

!̸̶͚͖͖̩̻̩̗͍̮̙̈͊͛̈͒̍̐ͣͩ̋ͨ̓̊̌̈̊́̚͝͠ͅ

If you remove the preceding ! then it spreads out.. what's going on with this craziness?