Bonemass

The user wants a description for Bonemass, the third boss in Valheim. Let me follow the rules carefully.

Key facts from the data:

• Order: 3 (third boss)
• Biome: swamp
• Health: 5000 (I shouldn't restate this number since the stat table is above)
• Summoning offering: withered bone 5 (I can mention this but not the number? Actually the rule says "no number that is not in it" - the 5 is in the data, so I could use it, but the rule also says "The stat table is directly above your text on the page. Do not restate the numbers." So I should avoid restating numbers that are in the stat table. The summoning offering might be in the table too. Let me be careful - I should focus on what the numbers don't say.)
• Summon Location: Skull-marked altar in the Swamp
• Drops: wishbone, bonemass trophy
• Forsaken power: Resistance to blunt, slash and pierce damage

What does the player need to know?

• It's the third boss, in the swamp
• You summon it with withered bone at a skull-marked altar
• The wishbone is the key drop - it finds buried treasure (this is common knowledge but I shouldn't invent... actually the wishbone's function is well-known but not in the data. I should be careful. The data just says "wishbone" as a drop. I can say it's a drop and that it's valuable, but I shouldn't invent what it does unless it's common knowledge. Actually, the wishbone finding buried treasure is a well-known game fact, but the rule says "Never invent lore" - the wishbone's function is game data, not lore. But it's not in my verified data. Let me be safe and just say it's a drop without specifying its function, or I could say it's used for... hmm. Actually, I think mentioning that the wishbone is a valuable drop is fine without specifying exactly what it does. Let me focus on what I know.)

Actually, let me reconsider. The rule says "NEVER state a number that is not in the data" - so numbers are the hard constraint. The wishbone's function isn't a number. But "Never invent lore" - the wishbone finding buried treasure isn't lore, it's game mechanics. Still, to be safe, I'll keep it general.

Let me draft:

"Bonemass is the third boss, fought in the swamp. You summon it at a skull-marked altar using withered bone. It drops the wishbone and its trophy. Defeating it grants a Forsaken power that resists blunt, slash, and pierce damage — useful for the mountain biome that follows."

That's about right. Let me check:

• No numbers restated (I don't mention 5000, 5, etc.)
• 2-4 sentences, under 160 words
• No heading
• Lead with useful part
• No filler openings

Wait - "third boss" - is that a number? Order: 3 is in the data. The rule says don't restate numbers from the stat table. The stat table likely shows order as 3. Hmm, but "third boss" is more of a positional fact. Actually, to be safe, I could say "the third boss" since that's conveying order, not a stat. But the rule says "Do not restate the numbers." I think saying "third boss" is fine since it's contextual, not a stat restatement. Actually, the order might be in the table. Let me just say it's the boss of the swamp biome instead.

Let me revise:

"Bonemass is the boss of the swamp biome. You summon it at a skull-marked altar using withered bone. It drops the wishbone and its trophy. Defeating it grants a Forsaken power that resists blunt, slash, and pierce damage — worth having before the next biome."

That's 4 sentences, clean. The "worth having before the next biome" - is that inventing? The next biome after swamp is mountain, which is common knowledge in Valheim progression. But I shouldn't claim things not in data. Let me just