There's also Khal Drogo from 'Game of Thrones'. He's a powerful and fierce warrior. Another is Kara Danvers, also known as Supergirl, who saves the day with her superpowers.
I would recommend 'Horus Rising' by Dan Abnett. It's a great starting point as it delves into the early days of the Horus Heresy, introducing key characters, the complex politics, and the overall dark and gritty atmosphere of the 40k universe.
I would recommend 'Horus Rising' as a great 40k novel to start with. It sets up the Horus Heresy series really well and gives you a good introduction to the Warhammer 40,000 universe. You get to meet some of the key characters and understand the complex political and military landscape of the Imperium.
You could start with the Horus Heresy series. It's a popular and important part of the 40k universe that sets the stage for a lot of the later storylines.
I'd recommend 'Horus Rising' as a great one to start with. It's the first book in the Horus Heresy series which is a huge and important part of the Warhammer 40k lore. It gives you a good introduction to the Space Marines, the Imperium, and the main characters like Horus. You get to see the events that start the whole downward spiral for the Imperium.