If Slade could compromise his healing ability, then Slade has this.
Problem with that is, most environments that compromise Logan's healing would also kill Slade outright.
Drowning him is the easiest way to kill Logan, for sure... short of throwing him into the Sun, suffocation (some sort of vacuum environment), or dropping something on Logan that would be too heavy for him to lift off himself.
.. and yeah, the writing (I'm looking at you, Civil War Wolverine) that had Logan reduced to just his skeleton, and conversing with Jean Grey's ghost before regenerating enough to be alive again? A unique, albeit ridiculous, premise; enough with that sh!t. If Logan's reduced to a skeleton, he's dead. Case closed.
Slade calculates faster than anyone, but Wolverine's actions make it hard to know what he'll do next. Short of Slade taking Rahne or Kitty Pryde (good luck) hostage, he's impossible to predict. Especially these days, as he thinks before he swings his claws... I love the leadership role he's in now.
