/execute particle Leaves a False Particle Trail to 0,0,0

Exact command: /execute @e[type=WitherSkull] ~ ~ ~ /particle cloud ~ ~ ~ 1 1 1 0 100 force

Note that the following works on "force" as well as "normal" and was also tested with "explode". I explain in the below video, this bug is hard to describe. Also even if there is no WitherSkull present, the black shadow appears, although the above flickering cloud does not.

https://www.youtube.com/watch?v=_0T_lN0mt94&feature=youtu.be