Can uses stack?

yes and yes

You will most likely need to do NG++ to get some of the spells anyway, so you can still platinum. Just remember in NG+ to leave him imprisoned.

R.I.P navlaan will invade you a lot of times and next to tough enemies

That happened to me too so I started over again now i have 2 builds

Just ng+ the game and try again :v

RIP OP Geyser

the Good ole geezer

You could just farm the hallows in the rat covenant area that's down in the pit. Believe it or not, they actually drop the simpleton spice (albeit rarely). Just be in covenant of champions and you'll have infinite spice.

It's not too bad to farm, with Bonfire Asetics in Belfry Sol, it only takes about 2-3 minutes of running to grab 3 spices, so it'd take about 48 minutes

Made the edit

Imagine if this thing required only 10 int LOL

You actually CAN make it require 10 int, with only 48 Simpleton Spices.

it won't, all MLGS attacks count as a "weapon" attack, none are classed "Magic" despite it's full magic damage and R2 special, tried this myself as i wanted to see if MLGS could become an insane glass cannon weapon.

Not really