Dark Souls: Remastered · Weapon upgrade path
Lightning upgrade
Lightning upgrades reinforce weapons from +0 to +5 and add Lightning Damage; the source notes use in low-level PvP.
How it works
The path changes the weapon to deal Lightning Damage. The source says it is popular in low-level player-versus-player play because most armor and shields have low lightning defense. That popularity statement is the source's characterization, not a measured comparison. The stated reinforcement limit is +5.
Read the supporting references
Check the edition and source version for patch-specific details. Guide methodology.