 So you made a whole bunch of awesome shape keys, but in between now and then you deleted and added a lot of new points to the base body. And now your old keys are out of sync with the new base. Not a problem. Let's start with the easy solution. First make sure that all the relative two areas for all the keys that come from the base body are set to bases. This just means that they should all start with the same shape as the original. In my case, after I had created all my keys, I realized that the elbow was too skinny. So I went back to the base key and made it bigger. But the old keys still morph to the old elbow size. Now if you want to tell Blender that every shape key's elbow should look like the one that we have in the base, click your object, go to edit mode, click the base, select the points that you want to copy to all the other keys, go to vertex, and propagate to shape. You're done. So now if you check all the other shape keys, you'll see that they all have the same elbow as the one from the base. Now this is great, but the problem is one of my keys was an elbow specific shape key. Which means that even though I fixed the elbow for all of these keys, I accidentally lost the shape that I needed for this one. So if you find yourself in this situation where you don't want to propagate the shape to all your keys, you can do this one at a time by clicking one of the keys with the old shape, select the vertexes you want to change, and on the vertex, hit blend from shape. And down here, set this to basis. Uncheck add, and now you can see that these points are now in sync with the new base body. Another way you can do this is by creating a vertex group for specific keys and then telling the shape key to only affect the points from that group. But that way is a little trickier, so it's up to you. Anyway, I hope that helps. If you enjoyed this video, please don't forget to like, subscribe, and ring that bell. Hope you have a fantastic day, and I'll see you around.