You can combine multiple PowerPoint Presentations using Reuse Slides, VBA code, Cop-Paste. The 1st preserves formatting while the 2nd can merge any number of files.

Microsoft PowerPoint allows you to combine two or more presentations with different theme templates. PowerPoint includes a Keep Source Formatting option that retains the template format for each ...

How to Drag Slides From One PowerPoint to Another PowerPoint. If you've ever had to manually combine the contents of separate PowerPoint presentations by typing or copying and pasting slide ...

Learn how to fragment shapes & images in PowerPoint using the Merge Shapes feature. The Fragment feature overlaps shapes and turns them into small pieces.