I feel that the two heroes are equally strong in the early stage, but don’t fight the Sword Demon at the beginning, as you know he is passive. If you want to fight, you can retreat after playing passive, and kill him next time.
When going up, you should pay attention to the blood pool of the sword demon, which is the energy bar below. The higher the speed, the faster the attack speed, which is similar to the anger of the barbarian. Harass him when he's not angry, and don't fight him when he's angry.
Sword Girl is a late-stage hero. You should mainly focus on fighting well in team battles. Don’t deliberately duel with Sword Demon. As long as you perform well in team battles, various harvests will be harvested, you know! The economy will naturally pick up, and when the time comes, no sword demons will be ignored, and they will be killed immediately.