Perhaps the most effective weapon within Wesker Archives, "Zantetsuken" is only avaliable to those who've obtained the highest ranking on each scenario, including the bonus stages. Whilst it's damage output is still rather high for a handgun, it's true positive effects lie in its Critical Chance, it has a "90%" Critical chance, the highest within the game. On Normal Mode, it will almost always decapitate a Zombie, meaning that Crimson Heads are a very rare sight.
On other modes and against certain other creatures, instead of decapitating the opponent it shall blast them back and leave them dazed. To balance the mode, Zantetsuken, like the other 'Unlockable Weapons' aren't avaliable on Sadistic difficulty.
- The name, "Zantetsuken", is taken directly from the Final Fantasy summon 'Odin', whom wields a blade of the same name. It has the distinct ability of killing all enemies or dealing immense damage to all current opponents. It has a high fail rate, however.
- It's Critical chance is a sum obtained via: Wesker's number of appearances within the main series, 5. Then adding the amount of times he is playable, 4. And finally multiplying the total by 10. Hence... 90%.