Ok heres what the ship does. First... Its a nuke that seems to have a mini stun, and AOE damage. Second, it is an AOE buff for your teamates. The buff speeds them up (drastically helping melee fighters against ranged supporters) and allowing them to only take half damage. When the buff ends, they receive the OTHER half of the damage... 50% imediate, 50% later.
After reviewing his abilities, I highly recommend armlet as a core item, along with MoM. X marks the spot seems to be his key ability for two reasons. First is unbelievable ganking power, because that range is JUST enough to cast on an enemy while out of site range(hidden in the trees). Second is that he can use x marks the spot while in combat (having mom and armlet activated) to juke in numerous ways, or to set up the enemy for ults, as mentioned by gaylikeunicorn on another thread.
I understand why you would want to go and get cleave on him, but I feel its not as affective as MoM and Armlet. The reason being, the cost of his casts are pretty low, meaning that crazy mana regen isnt as critical. Also Armlet and MoM synergize better with the rest of his abilities especially to proc the passive from a good attack speed, and making the most of his slow/xmarks the spot.
Treads, BkB/blink, and crits would finnish him off well I think
p.s. I think blink would be pretty nasty on him... can't wait to try it!
p.s.s. I also could see a build with SnY - desolater - Treads - hyperstone(later ass currias) - vlads offering (to help in team battles) - heart