The idea behind the nuke build is to maximize Arthas' damage. Regeneration Master/Block and Rune Tap are the basic sustain that should be enough to keep you in the fights and in the lanes. A great Arthas knows when to engage and disengage, so your ability to soak the damage and use your abilities to create a weak enemy team for your allies to pick off will be your greatest strength.

Sindragosa is a really effective ultimate in that it can completely turn a game around when played right. At lvl 20 the upgrade is very powerful in that it forces your enemy out of position while allowing you to reach the high priority targets.

So why pick Embrace Death at lvl 16? Well, all the other talents in that tier are all fairly decent picks, but one thing Embrace Death does is to give Arthas the ability to cast 700-1000 damage nukes every 8 seconds in the late game from a distance. Why is this important? Well, Arthas is a slow Hero, and any damage he does will be pretty deadly as long as he will be in melee range, but a competent enemy team will be able to peel for the squishy Heroes if you run straight in. Embrace Death will allow you to solo squishy Assassins and Specialists by simply utilizing Arthas' missing health to deal that extra damage that will certainly kill them.

If you have issues reaching the backline of the enemy team then this build will help you create the opportunity to deal with those kinds of matchups. As long as you know when to be aggressive and when to retreat, you will have great success.