In After Effects, you can use some plug-ins and technologies to facelift the characters in the video. Here are some methods that may be useful:

Use plug-ins: There are some third-party plug-ins, such as SmoothKit of RE:Vision Effects and ReelSmart Motion Blur of RevisionFX, which can be used to slim face and smooth skin. Using tracking-based technology, these plug-ins can automatically detect and track faces and apply face lifting and smoothing effects.

Use masks and adjustment layers: In After Effects, you can manually facelift with masks and adjustment layers. You can separate a person's face with a mask, and then adjust the face shape with the effects of "magnification" and "distortion" in the adjustment layer.

Use deformation tools: There are some deformation tools in After Effects, such as "liquid deformation" and "fisheye distortion", which can be used to thin face. These tools can adjust the shape and deformation of the layer to achieve the effect of face-lifting.

It should be noted that face-lifting treatment needs to be used with caution. Excessive face-lifting may lead to unnatural and distorted effects, which should be adjusted according to actual conditions and needs.