[X] My Assistant

How would one make a decent looking text box on to a picture in a comic theme 3D work and a way of replicating that over hundreds of pictures in a similar manner.

Don't know how to do so myself.

I'm not sure I really understood what you need, but there are many apps for making text boxes and speech bubbles, starting with Photoshop, MediBang Paint, Procreate, Krita ... often also depends on countless plugins

https://www.youtube.com/results?search_quer...ubble+photoshop
https://www.youtube.com/results?search_quer...+medibang+paint
https://www.youtube.com/watch?v=tJ0pl0NufCo
https://www.youtube.com/watch?v=iZcncdf90Os

Then there are many other "Text Boxes/Speech Bubble Maker/Generator" apps, sometimes it doesn't look neat tho'
[play.google.com] https://play.google.com/store/apps/details?...ckers&hl=en
[www.canva.com] https://www.canva.com/features/speech-bubble/

For 3D comics/manga, I only know of some quick text box options in Koikatsu Party and Manga Maker Comipo, but I haven't fiddled with these apps since the last pandemic lockdown (IMG:[invalid] style_emoticons/default/heh.gif)
[store.steampowered.com] https://store.steampowered.com/app/1073440/__Koikatsu_Party/
[store.steampowered.com] https://store.steampowered.com/app/262490/M...a_Maker_Comipo/

I hope someone else can give better suggestions