Using transparency will make everything see through including the character. It is better to use one of the keying effects. It could be luma keying to get rid of a black background as long as black isn't used in the character itself or you could save it with an alpha channel and use that to remove the BG. You haven't said how you intend producing this character, are you an artist or an animator? Or are you going to download something from the Internet? You can do effects like making people and objects appear and disappear using dissolves and still frames of backgrounds and then wiping to them. You can also have split screen effects were for example you can have the same person onscreen having a conversation with themselves or chasing themselves around the garden. Other effects such as playing clips in reverse, ghosting and speeding up or slowing down clips are also possible.

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