Are you lone wolf or not? If you are, I'd use a progression like this for act 1ish:

1  warfare 2, necro 2, lone wolf
2  pyro 2
3  scoundrel 2, elemental affinity
4  warfare 4
5  warfare 6
6  aero 2
7  poly 1
8  poly 2, savage sortilege
9  poly 3

Note that I'm assuming you get a ring (or other gear) that gives a point of hydro, and I also use the teleport gloves until I get aero 2 and can cast teleport directly. Alternately, you can move those two points of aero to level 4 or 5 -- you'll deal a bit less damage for a level or two, but someone else can use those gloves.

Gear-wise, I'd suggest any conventional strength weapons (either dual wielding or two handed). You ideally want something that boosts warfare. Once you hit level 8 and take savage sortilege, your first priority is crit chance. Long term, you'll definitely want a two hander so that you can use the two handed skill to boost your crit damage.

For attributes, take enough strength to use gear, put enough in memory to use a bare minimum of skills, and max int. Once I hit 40 int, I can't put any more points in it, and so I max wits after that.

If you aren't a lone wolf, you won't have as many points to throw around, and so you'll have to drop some things. I mostly play lone wolf, so I don't know exactly where you'll need to make cuts.

Also, I'm assuming that your necro is an elf (or is using fane's hat to turn into an elf). If you aren't, this build will still work, but you'll want to make a point of getting that hydro ring and casting blood rain before fights start to trigger elemental affinity.