It could be significant in many ways. Maybe it's a unique take on the concept of tyranny. It might use the graphic novel format to reach a wider audience, making complex ideas about tyranny more accessible.
I'm not sure specifically as I haven't read it in detail. But generally, a 'tyranny graphic novel' might be about a story of oppression, dictatorship or the fight against unjust rule. It could feature characters who are either victims of tyranny or those who rise up to oppose it.
There's no way to be certain without reading the 'tyranny graphic novel', but some possible main characters could be a group of intellectuals who use their knowledge to oppose tyranny. They might be joined by a fearless journalist who exposes the atrocities of the tyrannical government. Another potential main character could be a family torn apart by the tyranny, with some members joining the fight for freedom while others are caught in the middle, and their story could be a central part of the narrative.
The main theme might be about the nature of tyranny. It could explore how tyranny rises, what forms it takes, and the impact it has on society and individuals.
One of the popular works might be his take on superhero stories. For example, his 'Watchmen' graphic novel adaptation was widely noticed. It had a unique and darker take on the superhero concept compared to the more traditional ones. The detailed art and complex characters really set it apart.
Snyder's graphic novels have had a significant impact. For instance, his unique visual style in the novels has influenced how movies are shot. The high - contrast, detailed and often gritty visuals in his graphic works have been replicated in his film adaptations. This has led to a new trend in superhero movies especially, where a darker and more 'realistic' look is preferred.