The Limitless Key is an Epic-rarity item in Sailor Piece tied directly to Shibuya Station's Gojo content. You use it to summon the Strongest of Today raid boss on Shinjuku Island, and the loot from that fight feeds into the Gojo fighting style, higher Ascensions, and the Shrine Domain Shard craft.
Where the Limitless Key drops
There are two farmable sources, and they suit very different playstyles. The boss route is fast per attempt but gated by a respawn timer. The mob route is slow per kill, but it works while you're AFK.
| Source | Location | Drop chance | Respawn |
|---|---|---|---|
| Limitless Sorcerer (Gojo) boss | Shibuya Station, road at the back of the map | ~30% (some builds report a guaranteed drop with pity/Luck) | Every 5–7.5 minutes after death |
| Strong Sorcerer mobs | Shinjuku Island, right side from the portal | ~0.6% | Continuous respawns |
The Gojo boss has roughly 4,000,000 HP and is a mid-game fight. You need to deal at least 10% of his health (about 400,000 damage) to qualify for loot, so a weak character can still get shut out on public servers.
Farming the Gojo boss efficiently
Step 1: Travel to Shibuya Station and head past the Yuji boss to the road at the back of the map. Gojo spawns there on a fixed timer that starts the moment he dies on your server.
Step 2: Burn him down quickly. If your DPS build can finish the fight in under a minute, you won't have to share the damage threshold with other players on public servers.
Step 3: Instead of waiting out the respawn, hop servers as soon as he's dead. On a fresh server, the boss is likely already alive or close to spawning, which compresses the effective cooldown.
Step 4: Stack Luck and Drop Rate before each kill. Fortune runes, the Eminence clan, Boss Kill titles, a Kitsune species reroll (+25% Luck), and Ascension/Skill Tree nodes all stack to improve your odds on the same run.
AFK farming on Shinjuku Island
Shinjuku's Strong Sorcerer enemies drop the key at a much lower rate, but they respawn in clusters and don't require a mechanical fight. With an AoE build, you can one-shot groups of five at a time.
Step 1: Teleport to Shinjuku Island and turn right from the portal to the Strong Sorcerer spawn area.
Step 2: Equip your strongest AoE sword or fighting style and set a repeat keybind or macro-safe skill rotation. The goal is to clear the pack faster than it respawns.
Step 3: Layer Luck and loot boosts. Fortune Spec Passive and the Eminence clan increase per-kill loot quantity, which matters more here than raw kill speed.
This method is best used as background progress while you wait on boss respawn timers elsewhere. Don't rely on it as your primary source.
What the Limitless Key unlocks
The key is a summon item for the Strongest of Today boss, a raid-tier fight on Shinjuku Island. Take the straight path from the portal to find the Strongest Boss Summoner NPC, hold E to interact, and select the difficulty. Normal costs one Limitless Key, and each higher tier increases the cost.
Using two keys on the summon spawns the Gojo V2 version, which has better drop tables but significantly more HP and damage.
| Strongest of Today drop | Approximate chance | Primary use |
|---|---|---|
| Reversal Pulse | 15–25% | Gojo fighting style unlock |
| Six Eyes | 6–8% | Gojo fighting style unlock |
| Blue Singularity | 2–3% | Gojo fighting style unlock |
| Infinity Essence | 0.65–0.9% | Ascension, Shrine Domain Shard craft |
The boss has around 125,000,000 HP and a damage timer, so you'll typically need a team or a late-game build to clear it without wasting the key.
Limitless Key vs. Limitless Ring
These two are easy to confuse because they share the Gojo boss. They are not interchangeable.
| Item | Source | Used for |
|---|---|---|
| Limitless Key | Gojo boss (~30%) or Strong Sorcerer mobs (~0.6%) | Summoning Strongest of Today |
| Limitless Ring | Gojo boss (~8%) | Gojo fighting style quest, Ascend 2 |
Farming the boss gives you a shot at both items on the same kill, which is why Shibuya Station is the more productive long-term location even though the mob farm is more relaxed.
Luck sources worth stacking
Drop rates on both the key and the rarer raid materials scale hard with Luck. The most impactful boosts are the ones that stack multiplicatively rather than overwriting each other.
- Kitsune species reroll for +25% Luck
- Eminence clan for increased loot quantity
- Fortune Spec Passive
- Boss Kill titles equipped in the title slot
- Runes leveled through the Rune system
- Ascension and Boss Rush upgrade nodes that grant Luck
Get your Luck setup finalized before you start burning Limitless Keys on Strongest of Today. Each summon is a one-shot attempt, and under-stacking Luck is the most common reason players walk away with Reversal Pulse but no Infinity Essence after ten runs.