The Bloody Onion's normal physical attack is a ramming attack that carries a chance of knockdown due to its large size and power. Its most dangerous Special Attack is Onion Fall, a distance drop of onions that can hit multiple targets and cause knockdown. Onion Burp is another dangerous attack, a three-hit attack in a line that can hit multiple targets that are grouped close together. Burning Onion is a distance fiery drop attack on one. Finally, it can use Murmur to heal an ally (either another Bloody Onion or a Leaf Egg) for 5700 HP and that ally need not be in critical status.
The Bloody Onion is the most fearsome opponent in the Woodblock Groves due to its high defense and powerful set of attacks. Despite this, it can be reasonably easily defeated with the right strategy. Unless farming for EXP, any Leaf Eggs on the field should be taken out first to prevent them from transforming into Bloody Onions. Leaf Eggs have a high probability of simply moving into the light to transform unless there are multiple targets grouped close around them. The Bloody Onions generally will not move back into the darkness once in light, but can be knocked into it using Special Attacks that carry a knockback effect.
Unless your characters are overleveled, any character other than Jazz will probably have trouble dealing much damage to Bloody Onions using their normal attacks and many attacks may simply do zero damage. One of the simplest ways to deal with this is to simply use Viola's Hawk Eye to mark the Bloody Onions for damage. Once they are marked, they will go down easily to any characters' normal physical attacks, followed up by a special with some Echoes built up. Alternatively, have either Allegretto or Falsetto move to melee range on one that isn't marked and have them simply unleash their Special Attacks without any Echoes. By doing more than one Special Attack per turn, they can defeat the Bloody Onions swiftly. If Viola isn't needed for Hawk Eye, she should use Heal Arrow to keep the party well-healed.
Bloody Onions can prove something of a challenge in Encore Mode, as all of their stats, including defense, are greatly increased. Hawk Eye remains an effective choice to neutralize their defense, and going into the battle with Echoes already built up in order to launch a Harmony Chain is another effective strategy.
- The Bloody Onion is the first opponent in Eternal Sonata that is actually strong when in the light, but becomes a weak form when in the darkness.
- In the North Center area of Woodblock Groves, there is a motionless Bloody Onion opponent. If the player has been participating in the trading sidequest, then when the player examines the onion, Allegretto will use the Winder acquired from the man at the Cantabile Inn to make it move. It will exit the area and Allegretto will find an Empty Vase in the space that it left. The player can then return to the Adagio Swamp and use the Empty Vase to splash water on the motionless Blue Gil in order to acquire a Power Ring accessory, with increases STR by 10% for any one character.
- In the Xbox 360 version of Eternal Sonata, the Leaf Egg actually gives more EXP despite it being a much weaker opponent. Furthermore, the Bloody Onion does not seem to carry the high defense associated with it in the PS3 version and is much more easily defeated. Additionally, it does not seem to use its Special Attacks nearly as often, being more likely to simply close range to melee for normal physical attacks.
- This opponent always appears in the field in this form, never in its dark form as a Leaf Egg.