updated for 2.0
weapon enchancement scrolls are used to upgrade your weapon up to 10 times each upgrade makes your weapon better. you can buy scrolls at the masters shop for 10000 gold or you can kill monsters and randomly find them every monster can drop a scroll heres a list of the chances of them being droped:
killa chicken 1/10,000
wooly bear 1/9000
animated tree 1/8000
orc 1/7000
toxic spider 1/6000
black horror 1/6000
sleepy spore 1/5000
dry bones 1/4000
bone archer 1/3000
zombie 1/2000
blue horror 1/1000
wet current 1/975
gold lizard 1/950
ghast 1/925
lit lizard 1/900
nematoad 1/875
ogre 1/850
necormancer 1/825
vampire 1/800
lesser demon 1/775
pink horror 1/750
gem hide worm 1/725
killer vine 1/700
mystic frog 1/675
stoned collosus 1/625
gold shroom 1/600
diffusional monster 1/575
leviathan 1/550
crimson hellkite 1/525
nigthmare 1/500
demon 1/400
lich 1/300
lava golem 1/200
sky reaper 1/100
spawn of nature 1/95
joo lizard 1/90
beast of desctruction 1/85
mutated sludge monstrosoty 1/80
greater demon 1/75
tri elemental 1/70
mr. smiley 1/65
force of nature 1/60
ancient demon 1/55
sacred warrior 1/50