Mission Build

I just started on my assassin, I have him at lvl 20 and I want to try to get him through as many missions as possible by myself, as in no other real players but having heros and henchies. So I was wondering what would be the best build for NM missions and HM missions, or would it be the same? Thx for any help.

Most builds are designed this way, as people tend to only play with others in hard spots.

If you have all of the campaigns and Eye of the north, try to get the three necro heroes first. If you can get the sabway/discordway builds on them, you should be fine in terms of healing/damage.

I myself use discordway heroes, and my sin has the crit scythe build on it. Other than that, Monk hechies for healing, Rits/Paragons henchies for support, and Ele henchies for damage

A lot of it is preference in what you like as a build. I myself prefer the Sabway build to Discord for my Melee characters. Splinter Weapon is awesome with Death Blossom in my experience. My build that I run varies from area to area and I have gone through all campaigns.
Can't remember the Atrributes but I hope this will help give you an idea.

Assasin's Promise (E)
Unsuspecting Strike
Fox Fangs
Death Blossom
Impale
Entangling Asp
Signet of Toxic Shock
Feigned Neutrality or various others depending on area. Lightning Reflexes if Ranger Secondary usually for added defense and IAS

Obviously this can be changed to suit your preferences. I have played through and it has worked for me.