RE: Share Your Battle - Martyr Ability Is A Gamechanger

When a character with the Martyr ability dies in a battle, it gives adjacent characters +1 to all stats. This ability will put increased importance on positioning of characters on the battlefield, as its full effect will not be captured if it is in the first or last position when it dies, and it's also important that the intended characters are adjacent to it when it dies to receive the buff.

From the Splinterlands official post