Gerald Robotnik's Diary has kept several diaries during his lifetime, documenting his research and thoughts.
In Shadow Saga, Gerald created a last piece of his diary during his imprisonment at the hands of the Government (this piece of his diary of introduced first).
I don't quite know or understand of what happened or went wrong. Was it a mistake to create the ultimate life form? When I began my research, I only wanted to do good and would be something that would benefit mankind. But the leaders of the project feared I was taking this research too far and dangerous and were worried that I'd used it to take over the world. So they sent the military guards aboard on the Space Colony ARK that day. They were under orders to sieze and shut down the research project that I had been working on. My colleagues at the research facility, my granddaughter Maria, I hope you are all safe.
The colony was completely shut down, probably to keep the prototype from falling into the wrong hands. The ARK was shut down under the premise that there had been an accident.
During the Raid of the ARK, I witnessed one of the guards took Maria from me, and was to be enlisted for transfer. She has been meaning everything to me and I couldn't bear the thought that the goverment would be doing these things to Maria after everything I've worked for and because of my research. I lost everything. I had nothing more to live for... I went insane. All I keep hearing inside my head is "revenge" and have my life to take on a new purpose... somehow, someway. I got scared as I was no longer able to control my thoughts. All I could think about was insted of helping people, I would get revenge on them for her and that I wanted it all to end. Night and day I've planned, so long after I am gone, my revenge will be complete.
I've done it! My greatest design is now complete! Based on my original projections, I was able to complete my project, Shadow. My enemies think they have defeated me as he for now sleeps, but one day he will be reawaked upon only your heart's desires. I have left everything behind even my last instructions for Shadow and have complete faith that he will follow and carry out without question for I have designed his mind to be perfect, pure. I will leave everything to him. If you wish to your hearts's deepest desires, release and awaken him, Shadow, will bring total destruction!
In Rivals Saga, it is revealed that Gerald also kept a diary regarding his research on a powerful being named the Ifrit, a terrible creature that exists in another dimension.
- Gerald's diary may have information on his other creations such as Artificial Chaos and more information on Biolizard.
- The password for Gerald's diary is "Ma-Ri-A," the name of his granddaughter.