With Wolverine’s immense sense of personal honor, it makes sense that he would opt for Wonder Woman’s way of healing herself via the Amazon technology of the purple healing ray instead of his omnipresent healing factor that ultimately calls his honor and skill into question. Having trained as a samurai and as a World War II soldier, Logan has a code of honor that extends to multiple battlefields and cultures where he risks harm and death. Yet, a combatant’s fighting prowess—when they are so prolific at self-healing that their body is constantly recovering from damage—is hard to gauge.
The purple healing ray is an invention borne of Amazon ingenuity, designed to heal combatants only after the battle is over and wounds have been sustained. This ray, which Wonder Woman claims to have invented herself in Wonder Woman #237 by Gerry Conway, Jose Delbo, and Vince Colletta, can be used in lieu of stitches to heal wounds of varying severity. It has existed for 80 years, most notably healing Stephen Trevor after his plane crash led to injuries that would have killed him. Wolverine, on the other hand, has a regenerative healing factor that rapidly heals damaged tissue, even mid-battle.
Wolverine’s mutant healing power keeps him from truly testing his mettle, since he can shrug off fairly severe injuries. Depending on his opponent, there are times where the element of risk is completely gone, making evasive and defensive maneuvers just for show. Though he is steeped in the strategy and skill of samurai and soldiers, he is never able to claim that this training alone is why he won.
Though Wonder Woman has the technology to heal, the fact that her recovery comes afterward means she is acutely aware of the damage she has sustained. Even if only for the brief moment until she can use the healing ray, she still bears the brunt of her mistakes. Wolverine, on the other hand, can have his skin seared from his body and still recover, as he did after Nitro's explosion in Wolverine #48 by Marc Guggenheim and Humberto Ramos. This means that Diana must use her warrior skills in all matches against evenly-matched or overpowered foes, adding to her appeal as one of the year's most compelling comic characters. Wolverine’s healing factor means he has a built-in safety net.
His healing factor has saved Wolverine from horrific injuries, such as having adamantium fused to his bones or Magneto delivering one of comics’ most excruciating moments, ripping that same metal out. In the end, Logan is fortunate to have this superpower, but one can’t help but wonder if he’d turn it off for select battles, allowing him to really test his skills. Until he can, Wonder Woman’s method of healing allows her to maintain her warrior's honor, whereas Wolverine’s healing factor leaves him with far fewer fair fights.