Can the Oathbow's Sworn Enemy feature outlast the attunement?

Question

Consider the Oathbow:

Requires Attunement

[...]

When you use this weapon to make a ranged attack, you can, as a command phrase, say, "Swift death to you who have wronged me." The target of your attack becomes your sworn enemy until it dies or until dawn seven days later.

[...]

While your sworn enemy lives, you have disadvantage on attack rolls with all other weapons.

Say a PC attuned to an Oathbow were to use this feature to target a creature. The creature then kills the PC, but a friendly cleric uses Revivify on the PC. The PC is then unattuned to the Oathbow.

Does losing attunement prevent having disadvantage on Attack rolls with all other Weapons while the Sworn Enemy is alive (or 7 days passed)?

If so, does regaining attunement enables this feature once again, assuming the Sworn Enemy is still alive?

Answer 1

Losing attunement will prevent having disadvantage.

The following passage is from the attunement rules in the Dungeon Master's Guide (p. 138):

Without becoming attuned to an item that requires attunement, a creature gains only its nonmagical benefits, unless its description states otherwise. For example, a magic shield that requires attunement provides the benefits of a normal shield to a creature not attuned to it, but none of its magical properties.

The tense of the first sentence could be ambiguous ("becoming attuned" sounds like a one-time requirement), but the example clarifies the meaning: while you are not attuned to a magic item that requires attunement, you can't benefit from its magical properties, even if you were attuned to it in the past, since it's the current attunement state that matters.

So even if you were attuned to the oathbow once before, you cease to benefit from any of its magical properties when you are no longer attuned to it, treating it as a mundane bow from then on. Since you no longer benefit from having a sworn enemy and the bow is treated as mundane, there's no reason you would have disadvantage on attack rolls with different weapons.

In addition, once you lose attunement, you lose (not suspend or defer) your sworn enemy, so regaining attunement later does not reinstate that sworn enemy. Rather, when you regain attunement, you start with a clean slate without any lingering benefits from a prior attunement.

Answer 2

The DM decides, but RAW is ambigious

Without becoming attuned to an item that requires attunement, a creature gains only its nonmagical benefits, unless its description states otherwise. For example, a magic shield that requires attunement provides the benefits of a normal shield to a creature not attuned to it, but none of its magical properties.

So you would lose "all magical properties" when you are no longer attuned, but I think it's fairly safe to argue that having "disadvantage with all other weapons" is not a benefit, it is a penalty.

This leaves a few options for your DM to take:

• The penalty is a magical property of the bow, you are no longer attuned, therefore you no longer take the penalty
• You no longer have a sworn enemy, but the penalty is an ongoing effect akin to a curse, because there is no clause for 'or you lose attunement from this item' in the 7 day penalty clause.
• You still have a sworn enemy, because the line about them becoming your sworn enemy does not state it depends on remaining attuned to the oathbow, and the DM decides from there what this means for the disadvantage.

But beware munchkins

RAI, it seems extremely likely that you're intended to suffer the penalty for 7 days. If your DM allows you to simply unattune from the object to get rid of the penalty, congratulations, you can now unattune during your next short rest, not worry about the penalty for 7 days, and after a week attune to it again if the DM rules that your chosen sworn enemy persisted while unattuned. Even better, simply attune again the same day in a second short rest and pick a new sworn enemy if the DM rules that the sworn enemy disappears entirely when you unattune.

This is obviously not in line with what the item's flavour is supposed to do. If the downside was that easy to remove, it would have just been "until your next short rest" or something along those lines.