if you want a good build for grinding, skip demo, and go for dark pact in afliction. once you hit 46, get iHoT and you can grind multiple targets at once. a couple of the talensts are your choice up to dark pact, but make sure you have imp drain soul to get mana back at the end so you can continue to grind faster. 1 point into shadow embrace helps with draing life. imp CoA vs imp Corr is your choice. at lvl 43 im not sure if ur +dmg will be significant enough to make imp corr better, but idk you character. imp life tap isnt exactly needed, but thats your call. amp curse/ CoEx arent really needed for grinding, but i always liked having a bit of pvp in my builds incase i wanted to pvp. Just once you get to 45-46 make sure to get iHoT, and you can grind a couple mobs at once, and drain soul just before they die to get al ur mana back.