New Graves Passive idea- "End of the Line"

NEW passive: Upon taking lethal damage, Graves uses his special bullet shell, "End of the Line"(from the New Dawn cinematic), in a last ditch effort to create a huge AoE explosion around him.

The damage would be AD based and either damage ALL units around him or just enemy ones, haven't really decided.

You could move his old passive to one of his abilities or something, but, with the coming marksman update, I though this would be a cool thematic thing to spice things up a bit.