The Grass Sword was Finn's sword from the episode "Blade of Grass" which replaced Joshua's broken demon blood sword. He gets it from the Grassy Wizard but he had cursed it so the sword would be stuck with finn for all of eternity.
Powers and Stats
Tier: At least 7-B, likely 6-C | 5-C
Name: Grass Sword
Origin: Adventure Time
Classification: Cursed Sword
Powers and Abilities: Regeneration, Can cut through spirits (Killed Finn's fear of the Ocean), Size Manipulation, Body Control (Can grow in size and change shape), Statistics Amplification (Can increase its power dramatically at larger sizes), Plant Manipulation (Limited to itself), Curse Manipulation (Limited; it was created to curse its owner into wielding it forever), Biological Manipulation (Completely changed Finn 2s anatomical structure into that of grass)
Attack Potency: At least City level, likely Island level (Can cut nearly anything without much effort at all. Tore a giant grass monster with ease. Matched the Finn Sword during during the battles against Bandit Princess) | Moon level (Cut through Orgalorg, The Breaker of Worlds and even cut off The Lich's arm)
Speed: At least Subsonic by itself (Cuts incredibly quickly, usually faster than the eye can see), Massively Hypersonic+ under Finns control (Tagged Orgalorg)
Durability: Unknown (Can regenerate) | Moon level after merging with Finn
Range: Several meters
Weaknesses: None notable | Appears only in extreme situations
- Tore a giant grass monster with ease
- Killed The Fear Feaster of its own accord, despite him having said, "No mortal blade can harm the Fear Feaster."
Key: Pre-Merging with Finn | After merging with Finn