I'd say Whitebeard's is worse because the guy was already sick and on top of that old? Garp was just old and not sick and still destroyed prime Kuzan, and Luffy, well, Luffy got pierced by a sword with an abnormal ability, but Luffy's young and still, though considering it's a sword with an abnormal passive and Luffy's weak against cuts, it could even be WB >= Luffy > Garp.