Assessment needed for Silly story generator

Hi guys, please some one should kindly asses my Silly Story Generator. The link is given below. Thanks.
https://codepen.io/lawman4sure/project/editor/ZGzyvB

You only need to cut the : from the random string arrays.

It was 34 centigrade outside, so : Willy the Goblin : went for a walk.

And instead of creating a whole if condition to change the insert(z,x,y), you could replace the string inside the text with a varible/let/const