Some Combat Suggestions

[Ori]

1. Per-hit fixed % lifesteal → Lifesteal as a % of damage dealt.
2. Per-hit fixed % concentration steal → Concentration steal as a % of damage dealt.
3. Plate armor is too advantageous → There should be unique merits for cloth, leather, chainmail, and plate armors respectively.
4. Regardless of enemy patterns, indiscriminate use of skills → Concentration build needs a nerf.
5. More varied item options and penalty options needed (however, boring options like gaining copper on hit should be removed).
6. Some options of secondary weapons that apply when the primary weapon is used need correction (e.g., lifesteal and concentration steal on hit).
7. Several currently unapplied options (e.g., attack speed) need to be activated.
8. Most legendary weapons, which are like trash, need improvement.
9. For ranged dealers like mages and archers, using melee hits or parrying to recover concentration is not a good method.
10. Stat reset needed.

[Nechrond]

@Ori

1. Per-hit fixed % lifesteal → Lifesteal as a % of damage dealt.
2. Per-hit fixed % concentration steal → Concentration steal as a % of damage dealt.

These sound like good ideas at first because they are what you want, but they are what everybody wants and therefore usually end up destroying build diversity and balance.
As soon as the ability exists it becomes mandatory.