But there's no way to get an increase in max health for the zat. It's getting that first kill that's dangerous. Once you are wading in a sea of enemies you are basically invincible so the hard part is getting there. Eyelander heads help you get the combo started. Plus health from kills gives you overheal while zat only heals you up to max health.
Hmm. I recognize the merits of both the Zatoichi and the Eyelander. However, I would lean in favor of the Zatoichi because you don't need to purchase overheal, so you can put more points into attack speed and damage, so it's better earlier on. The Eyelander might be better later on, but I enjoy wading into a crowd of bots and just smashing them to bits. For one thing, I lose enough health that the Zatoichi is more like gaining 150 health, which is more than the Eyelander's health from kills. Of course, the Zatoichi doesn't scale in terms of power and speed like the Eyelander does, but you can also lose the Eyelander's benefits. Overall, I would say that the Zatoichi is lower-risk lower-reward, while the Eyelander is the opposite. I just prefer the safer bet.
Also, I can't believe how few scouts use the Sandman/Mad Milk/Force of Nature combo. With a decent team, you can eliminate the giant robots so easily. Permanent mini-crits from the Mark of Death? Yes, please! (I think they're permanent anyway. They last a dang long time.)