Here are some Warhammer 40k names fitting for a Mechanicus character, incorporating various styles and levels of formality:
Formal & Hierarchical:
More Technical & Functional:
Mysterious & Ominous:
Names with a more human feel, but still fitting the Mechanicus aesthetic:
Remember that you can combine elements from these examples to create even more unique names. For example, you could combine "Magos" with a more human-sounding surname like "Magos Biologis Anya Petrova" or create a more descriptive title like "The Iron Oracle of Mars." The possibilities are vast within the lore of the Adeptus Mechanicus.