With all the talk about how an Easy Mode would affect Sekiro: Shadows Die Twice, it was just a matter of time before a modder took things into their own hands. In this case, it was a modder known as uberhalit, as he took the time to add the ability to add both player character, and global world speed, to his FPSUnlockerAndMore mod.
The mod also has some other very useful features as well. It unlocks the framerate, for those using high refresh rate monitors, adds custom resolutions with 21:9 widescreen support, and lets you tweak the FOV. Now, it is a shame that the game itself doesn’t allow these, but modders have continually opened up these features in From Software games on PC.
About manipulating the speed of the game, it allows you to alter your speed, and the world speed, independently. This means you can give yourself the edge by being a little faster than enemies, or just slow the whole thing down a little should you prefer. This will make things like timing blocks and deflections much easier.
If you want to try it out, you can grab the mod over on Nexus Mods.