The metals which are pretty nasty when present into wounds do not suit well for making a blade: alkaline metals like sodium can be really dangerous when in contact with water based solutions, causing burns, but they are pretty soft.

The closest you can get is having a bladed with a rough surface (aside from the cutting edge), where you spread quicklime (CaO) before each battle.

Being highly reactive with water, quicklime would have a nasty effect when dispersed into the wound upon cutting the flesh of the victim.

When the blades clash during the battle would disperse powder of quicklime, which landing on sweaty skin of unprotected fighters could also cause burns or irritation. But then your fighters cannot fight a la 300.

Quicklime was commonly used for building in middle age, and its reactivity with water was known.

The metals which are pretty nasty when present into wounds do not suit well for making a blade: alkaline metals like sodium can be really dangerous when in contact with water-based solutions, causing burns, but they are pretty soft.

The closest you can get is having a bladed with a rough surface (aside from the cutting edge), where you spread quicklime (CaO) before each battle.

Being highly reactive with water, quicklime would have a nasty effect when dispersed into the wound upon cutting the flesh of the victim.

When the blades clash during the battle would disperse powder of quicklime, which upon landing on the sweaty skin of unprotected fighters could also cause burns or irritation. But then your fighters cannot fight a la 300.

Quicklime was commonly used for building in middle age, and its reactivity with water was known.