|Breath of Fire III Boss|
ヘルライダー Heruraidaa (Hell Rider)
If Ryu does not know the Skill Kyrie, then equip Ryu with Protectors, Force Armor, a Light Bangle and a Ring of Ice. As Ryu is now protected against the effect of Sleep and Frost, he can now simply Attack until Arwan is defeated, healing when necessary.
Alternatively, Ryu can use Kyrie. Since Arwan is a Devil-type monster, Kyrie will instantly defeat him and the player will win the match without once taking damage.
A third option is to use Ryu's dragon form Tiamat, which is immune to sleep. Ryu can just whittle away at Arwan's HP until it dies.