In January 2023 I added Excalibur Umbra to my ongoing Hollowframe project, of which the goal has been to draw every warframe in the styles and themes of Hollow Knight.
My design for Hollowframe Umbra is very directly referencing The Hollow Knight, basically copying the pose nearly 1-to-1. I did still take liberties when designing Umbra's details to match his look in Warframe, most obviously with his head shape but also in the introduction of Umbra's U-shaped details and a larger prevalence of the orange Infection to mimic the visual effects of his Exalted Blade and to play with the design of his broken alternate helmet. If I were to go back to this I could change the pose a bit to better avoid copying, but at the same time I think it's also this shared pose that helps establish the connection I made.