Here are my interpretation of 2 rahis: The Archive Beast (Tarakona Nui) and the Cliff Screecher
Archive Beast (Tarakona Nui)
This creature was inspired by the Tarasque, a french dragon with 6 legs, a spiky turtle shell and a big jaw.
Like the Tahtorak, this creature is huge, and the model scale is not necessarly representative. Here is a size comparison with a toa.
And a turnaround

Cliff Screecher
A turnaround
Stud.io files and Breakdown photos
Archive Beast (Tarakona Nui) - Google Drive
Cliff Screecher (Peka Nui) - Google Drive
Custom parts links
Bionicle Pridak's Shark Tooth Blade Prototype by Scmdex - Thingiverse
Bionicle Crystal Spear by Scmdex - Thingiverse
My Stud.io Pack: Scmdex Pack - Google Drive
I hope you will appreciate these models. Every constructive suggestions to enhance the models are welcome.