The left-to-right mark character is an invisible control character. If you open up a text file in VIM containing such a character, you will see it as <200e> in Unicode.

If you want to get rid of all occurrences of this control character, you can do:

:%s/<ctrl>+<shift>+u200e<enter>//g

That’s <ctrl>+<shift>+u to enable entering the character by Unicode code points, followed by the actual character code and <enter> key. It will loke like this:

:%s/<200e>//g

However, not all terminals are supported.