I like this poem, it includes the notion of fear, both of the dark and the witches. It can be said that this is parallel to the human fear of the unknown. The first two stanzas do well at increasing the suspense, what is going to happen?

Now, the first comment is quite irrelevant. I'm not too familiar with terrycraft or steemit contests all that much (quite new on steemit, not new to poetry). I thought that a rhyme was required, but if not, nevermind this.

As for the critique. First of all layout. You could use a bold name or a header (no need for the apostrophes. I would appreciate if there was a little bit more punctuation (e.g. some commas at the end of some lines) to help with the reader's flow, as well as not having capitalised each first letter. These are subjective thoughts, but the more professional poems I read rarely have many capitalisations.

Regarding the content, there is little I would change. First line, you have a plural "hearts" and then "faints". Either you have to bring it to a singular or change the verb to plural, i.e. "faint". (Yes I know, sometimes silly mistakes get past our eyes when we are editing our poems, it happens to the best of us).

In the first stanza, "as the darkness" is repeated, and it the second time it is said that it thickens, which is almost identical to the "grows and looms". I would suggest something more descriptive, e.g. the darkness shrouds the coven's lair. Doesn't have to be that, but something more visible.

In the second stanza, I would not put "muttering" and "echoing in the same line. I would not expect mutters to be echoed. It is almost contradictory. One of them would suffice.

The third stanza is a bit underwhelming. Firstly, "monotonous chants" - not a huge fan of it. We are afraid of the unknown. The monotonous is anything but unknown, it would mean something that happens over and over. Not necessarily, but I would not classify witches chants or spells monotonous. Furthermore, the use of "chants" again. It's not bad in itself, but having mentioned it before, I would prefer something along the lines of casts, spells or curses. The last two lines have more potential. It is anticlimactic. You give us a terrifying suspense in the first two stanzas, and then leave us with "the coven strikes again". I would prefer if you describe the havoc they create, have something actually terrifying happen. The last words should be impactful.

Having said that, I might be a bit too over-critical. Especially since requested, I like to give all the opinion and feedback I can think of. It does not take away from the poem, which is good in itself. But as any 'art', it is subjective, and always have room for improvement. Not necessarily the poem itself, but as writers, we must always seek to improve. Feel free to drop on my page and leave your feedback, shred my poem to pieces :P