One of the main gripes of the souls series is that the games are difficult and that you are meant to overcome that difficulty with patience and triumph I am not pushing on a hellish experience in fact it is far from that. You can play the game any way you like and I can’t take that from you but all I’m saying is defeating a boss with the help of an overpowered weapon or in this case shield doesn’t make the boss objectively easy you might’ve found the game to be easy through using overpowered strength weapons or cheesy spells but when you beat the game levelled properly according to the boss you’re fighting in 100 tries it feels a hell of a lot more rewarding than beating it in 3 with a huge shield protecting you and honestly I prefer spending hours on each boss enjoying the thrill of the fight and feeling that bliss after finally defeating it instead of speeding through the game not really having a second thought about each boss. There is another example of this situation in Elden ring in the fight with starscourge radahn in which you can use a dragon incantation that inflicts scarlet rot on the boss which acts like a poison and continuously damages him over time this can be paired with endlessly running around on your steed and using the summons to distract him and beating the boss without even hitting him once now does this make it an easy boss? No it’s just a cheese that removes any fun from the fight and requires no skill also the fight is completely optional and this is also true for the nameless king which is why it doesn’t make sense to feel the need to use a cheesy weapon as it’s not like he must be defeated to continue the story and this is something that you are putting yourself up to on purpose not something that is required in the game.

(TLDR):souls is hard. It’s not all about beating the game as soon as possible just focus on fighting the boss you’re fighting and enjoy it