Convergence - To move towards a common point, the joining to become one.

Ah, that 'black misty thing' there is Hakura, the god of all evil.
The most malevolent and ruthless force in the multiverse. He takes many forms, but his presence is unmistakable.

Hakura (evil) takes many forms... this is his ghosty mist of doom form. I happen to like this form, I occasionally, in my mind theatre, see him take on a snakey mist and engulf things.
If you've ever seen the grudge (remake), the bit where Kyako kind of 'bled' through the cieling... that's a very Hakura thing to do.