5 / 10 / 15 / 20% of all incoming damage to the Sand Wraith is reduced and reflected to all enemies in a 1000 radius as Magic Damage.
Cost: 50-150 MP
When activated, the Sand Wraith takes 40 / 50 / 60 / 70 reduced damage (NOT PERCENT DAMAGE REDUCTION) for 4.5 seconds. All damage reduced this way is reflected onto all enemies in a 500 (cut in half) radius as Magic damage.
Purpose: This makes Wraith much more of a ganker without making him an absolute monster late game. In the early game, it makes Wraith a lot more resilient without making him unkillable (prohibitive mana cost and cooldown), as well as allowing him to towerdive for kills (Icefrog's original purpose when Spectre was introduced).
When ganking, this skill gives you five seconds of towerdiving time. At level 1, you can use the skill right off the bat to start hitting the enemy hero while temporarily ignoring the creeps beating on you. At levels 7-8, when you have Dissipate maxed, you'll pretty much be taking no damage from the tower while the tower is essentially hitting all enemy units. However, this doesn't really make Wraith that tanky come endgame; after the short duration, you're squishy once again and don't have 20% damage reduction like the old Dissipate.
PS: Yes, this is quite similar to Spectre's first dispersion. I'd like to see a return to that, but less overpowered with it's 100% uptime.