If not using shield during the battle the player gets temporarily:
Tier 1: Attack Speed Increased Low + Attack Damage Increased Low
Tier 2: Attack Speed Increased Medium + Attack Damage Increased Medium
Tier 3: Attack Speed Increased High + Attack Damage Increased High
Using google translator I not speak good english or good spanish.
The bonuses are too high, and the game shouldn't incentivize you to fight without a shield.