inb4, fail of the week.
Abbadon with 399hp, incomes Lina Laguna Blade with Aghanims.
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Also seeing as most people use Abbadon as a support I can't imagine many games where he gets a BKB. I'm guessing a hex is best to counter him, if the hex stops his passive that is. I think Lion would own him in games, just hex, finger his ass.
Hmm I just thought, his first skill takes a tiny bit of damage from Abbadon and either heals an ally or damages an enemy. If he uses his first skill when under 400hp will that also heal him?