If the Avenger were 2x black, they would take more damage from the Paladin's 3x white attacks. The way Grand Edition is set up. if the damage is being boosted (ie white attack VS black unit), it's increased even more for each white dot in the attack and each dark dot in the defender. So 3x white attack vs 2x black defense would double the damage-bonus compared to 3x white vs 1x black.
It does seem a bit imbalanced that the Avenger doesn't have a 3x black attack option, or at least a 2x black+1 red.
I think Kazan only joins after Esgares is defeated and Shiraha has re-joined an enemy country. You can only convert a knights to Shadow class units if Kazan or Shiraha is on your side and the knight is a male whose an expert ranger and with decent AGI and STR stats. You could try cheat codes to make it happen.
It does seem a bit imbalanced that the Avenger doesn't have a 3x black attack option, or at least a 2x black+1 red.
I think Kazan only joins after Esgares is defeated and Shiraha has re-joined an enemy country. You can only convert a knights to Shadow class units if Kazan or Shiraha is on your side and the knight is a male whose an expert ranger and with decent AGI and STR stats. You could try cheat codes to make it happen.