Hypernatural offers highly consistent characters, including on free plans. When you create a new video you'll reach a step titled 'Consistent Characters':

Hypernatural will automatically cast your characters using our Hypernatural Stock Characters or using characters from your custom character list. You can swap out characters before the video is generated, or create a new character (if you're on a subscription plan), by clicking the 'Replace' button:

In order to keep the faces consistent across your video, you'll need to enable the 'Use Consistent Character' setting. If this setting is disabled, your characters will not be consistent throughout your video.

Here's a video walkthrough:

You can also create characters before creating your video. Here's an article on how to create character.

If you want to regenerate an image or create a new image with a particular character in your video, all you need to do is use the character's name: