How to obtain it

Choose the Saw Cleaver from the starting weapon messengers in the Hunter’s Dream. If you already chose a different starter, obtain the Saw Hunter Badge to unlock the normal Saw Cleaver in the Bath Messenger shop. This guide does not use the Chalice Dungeon Uncanny/Lost variants as the beginner route.

Saw Cleaver : Weapons of the Workshop : Bloodborne

A Saw Cleaver overview; automatic captions misspell item names. The written acquisition guidance uses the linked weapon reference.

Darcblade · Source / open if playback fails

The footage and applicable version have not been fully verified. Use the sourced text answer for confirmed steps.

Use the two forms

Folded attacks are quick and carry the serrated bonus against susceptible beasts. The extended form trades that property for a different reach and attack pattern. Practice transformation attacks in a safe area; use spacing and stamina recovery instead of assuming one form is always stronger.

Can it last the whole game?

The community discussion and weapon guide both support keeping it through the main game if you upgrade it and build around its scaling. That is a viability answer, not a claim that it is the strongest weapon. Upgrade choice, gems and player comfort matter more than a blanket tier ranking.