Once I hit nightmare/hell/inferno difficulty the casualness of the game goes away and what blizzard thinks it a challenge turns to work. I'll have to stack mf in order to find good gear but can't kill anything cause I sacrificed for mf. I started playing d2 and I'm stuck on hell act 3. I'm a necro and things just don't die I'm maxed summon with curses with corpse explosion and other direct spells, problem is my skellys and Merc don't kill anything for me to use C. Explode it would be fine if I could tell my minions who to hit so I could focus one down instead is spreading out.
Again I just want to progress with a challenge and not get stuck.
Common D2 problem. You character is probably broken with poor skill allocation. In D3 you will be able to expirement with your skills to find something that you enjoy playing and is effective.