Crossbones is the best choice.
Other options that rely on AAR are Black Widow, Wasp and Gwenpool if you can keep the combo meter, Blade against villains, Elektra if you have 5/5 deep wounds or resonate and Medusa against robots.
Last but not least you can decide to take the damage and regenerate it. In this case there are Wolverine, Ghost Rider and (again) Blade.
ST+KM can nullify it during debuffs. Other than that, go with the aforementioned champs. X23 is a good option since she can regen and is DoT heavy. Other DoT heavy champs like AA, Dom and Gwenpool are good. With GP, after 50 hits, it won't proc anymore (kind of moot since one of you will be dead by that point).
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Other options that rely on AAR are Black Widow, Wasp and Gwenpool if you can keep the combo meter, Blade against villains, Elektra if you have 5/5 deep wounds or resonate and Medusa against robots.
Last but not least you can decide to take the damage and regenerate it. In this case there are Wolverine, Ghost Rider and (again) Blade.
Edit: Void is a great option too.