Well I couldn't find more information about other swords but from what I researched it seems berserker is the top 1 sword
but what are buffs?
Well, the buffs that the berserker gives in her transformation are many. The damage in general is increased by 2.1x. It also increases the sword damage by 1.5x. It increases the speed by 3x. It also increases the dash by 1.5x and there is a 5 probability that you a dodge and 1.5x damage reductionD
The buffs it gives are too many, which is why it is the top 1 sword.