@bobek: i would wait with such suggestions until we all have seen how he performes.
At first i didnt want to respond, but i changed my mind.
You are right, only when we see him we can truly suggest that, but i sugessted that cause i already feel that as a weakness, (and if you can feel it before even try, then it probably is), and in comparison with passive 2 erebus nightwalkers it is rather trivial.
10% chance to 1.5 crit is this:
let's say DA dmg is 100. In 10 hits he'll deal 1000 dmg. With that crit it will be only 1050 !!!, that's really small, 2 nightwalkers do better (plus they take the part of the dmg creeps deal, and you get hurt less). I already see how waste it will be to spend points in that skill when you have so many better active skills and passive speed & dodge to take (yes i believe 100% that active skill would be better). That crit skill will probably give 10% chance for x1.5/2/2.5/3 dmg and that is weak (4 skills for 3 times dmg, 10% chance?!!) Only if i'm wrong with that, and if it gives 1.5/2.5/3.5/4.5 (!) or increases chance to 15% on higher skill lvls, then i will be indeed wrong. But if it's as i predicted, then my suggestion is already, without even trying DA, the way to go.
Remember, in the end the dmg & chance will remain the same, i'm just saving 1 point for that skill to max it. (by putting it passively - by default - in the DA character)