It sounds like you need a VBA script that will go through each slide and on each slide go through each shape. Then go through and format the text for each of those shapes.
How does that sound?
If that sounds like a way you want to go I have included some code to get you started.
Code:
Sub FormatAll()
'Code that looks through each shape and then formats the text to
'a specific type of font.
Dim pst As Presentation, CheckSlide As Slide, CheckShape As Shape
Set pst = ActivePresentation
On Error Resume Next 'Skip over no text shapes and wordart.
For Each CheckSlide In pst.Slides
For Each CheckShape In CheckSlide.Shapes
'Times New Roman, 60pt, Bold, font color, Sentence case, no shadow, etc
With CheckShape.TextFrame.TextRange.Font
.Name = "Times New Roman"
.Size = 60
.Bold = msoTrue
.Color = vbBlack
'Add other attributes as needed.
End With
Next CheckShape
Next CheckSlide
On Error GoTo 0
End Sub
As with all code, be sure to save and backup your presentation before running.
Let me know what else you need.
Thanks