Elemental Katana (5e Equipment)

Weapon (katana), rare, (+1), very rare (+2), or legendary (+3) (major) (requires attunement)

This katana has been infused with an elemental gem enhancing its power, giving it an additional damage die of a specific magical type. The size of the damage die is determined by the weapon's rarity: 1d8 used one handed or 1d10 used two handed (rare), 2d8 used one handed or 2d10 used two handed (very rare), 3d8 used one handed or 3d10 used two handed (legendary). Once per day you may curse all creatures of your choice within 100 feet of you to have vulnerability to the katana's damage type for 1 minute (you can do this as a bonus action). By touching more elemental gems to the gem of the katana it can absorb them allowing you to unlock new sword skills and combos.