To win battles you need the following in the following order.
1. Highlevel hero. (This is the most important factor in winning duels)
2. High attack and High amour
Skills like empower And Wolf Curve blade or Wolf axe would be best. And also use Earth amours for chest, boot, Shield.
What skills to equip?
Passive skills are better than active skills.
The bests skills to equips are listed below.
1. Counter (Because the counter dmg cannot be absorbed with amour)
2. Empower ( Can increase your dmg rapidly)
3. Block (Can be useful in absorbing)