Lonely
Nature +10% Attack −10% Defense
Attack at the cost of physical bulk. Adamant or Jolly is almost always the better deal.
What it changes
Raises
Attack+10%
Lowers
Defense−10%
The multiplier lands on the final stat — ×1.1 on the one it raises, ×0.9 on the one it lowers — so it's worth more in absolute terms the higher that stat climbs. HP is never touched by any nature.
Berry flavours
LikesspicyDislikessour
Every non-neutral nature likes the flavour tied to the stat it raises and dislikes the flavour of the stat it lowers. This is what drives berry reactions, Pokéblock and Poffin results, and curry ratings — and it follows the listed nature even if a Mint has changed the stats.
Pokémon that fit this spread
Ranked purely by the gap between Attack and Defense in their base stats — the wider the gap, the less Lonely costs them. Base stats only; this ignores movepool, ability and format.
Changed your mind?
A Lonely Mint applies this same spread to any Pokémon without changing the nature it displays. Berry flavours keep following the original nature.
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The opposite trade: Bold
Bold runs the same two stats the other way round — +Def −Atk. Worth a look if you picked the wrong side.