Suikoden II
Double-strike
- Damage taken and received × 1.5
Suikoden III
A double edged sword rune as it deals 2× damage to an enemy but you'll receive 2× damage from them as well.
Suikoden IV
A rune that deals 2× damage both ways.
Suikoden V
Renamed Double Edge in Suikoden V, damage dealt and received is doubled.