catch them with flying down and spamming a direction along eastern or whatever - trip them to death. Easy as pie. Killed a ton of necros like this.

Alternately, work with someone who has detect invis.

Alternately, don't get slept and he can't do #### to you.

Seriously, village app versus necro under level 40, village app wins almost every time as long as he doesn't get slept.