Here's an example
Hildugrun, the "Blood drinker", sword of long forgotten hero of the north, whose pride and greed brought him to his demise.
1st - +1 "to hit" bonus, 1d4 sanity loss(both wielder and enemy)
2nd - +1 damage bonus, 1d6 sanity loss, save vs. fear for beastmen
3rd - +2 "to hit" bonus against beastmen, 1d8 sanity loss
4th - +2 damage bonus against beastmen. 1d10 sanity loss
Oh hell it a very long post, so sorry.
Ah and sorry for my poor english.