The album's three singles, "Hageshisa to, Kono Mune no Naka de Karamitsuita Shakunetsu no Yami", "Lotus" and "Different Sense", have all been remastered from their original releases.

However, since we worked with a Western engineer, it was difficult to discuss and communicate our ideas solely through the internet.

[5] Music videos were released for all three singles; "Hageshisa to, Kono Mune no Naka de Karamitsuita Shakunetsu no Yami", "Lotus" and "Different Sense".

In his review for AllMusic, Thom Jurek wrote that "Dir en Grey are a band in their own genre at this point, and Dum Spiro Spero is the farthest-reaching testament to establish that as fact more than opinion."

PopMatters' Dane Prokofiev noted in a positive review that "their music is eclectic and hard to classify into any one subgenre—except that they have the added fangirl-ish oomph of flashy appearances, thanks to their visual-kei roots".

He also singled out bassist Toshiya as deserving of praise for his performance on Dum Spiro Spero, "as his throbbing bass lines complement the technical guitar riffs well by adding a groovy kind of bad-ass attitude to the overall feel of the music.