Great Hammer customization question

[Nissatani]

Nissatani is now strong enough to use a great hammer so I was hoping I could get this https://darksouls3.wiki.fextralife.com/Spiked+Mace as Nissatani's great hammer? The spikes don't make it do any extra damage or anything I would just roleplay it that instead of doing all crushing damage some of it is also slashing/stabbing too.

Also I would roleplay some lore that it's a weapon design known and forbidden to her tribe because it's considered a weapon that's powerful but too cruel and barbaric to use against living things however Nissatani being separated from her old tribe and not liking how she had been treated by them wouldn't care.

[miyuka]

Gonna have to say no to that. What you have there is a mace, not a great hammer. You can't have one weapon and have it do the damage type of another weapon.

[Nissatani]

Yes ma'am. Thank you for the speedy reply!