Not only for warriors, but this also goes for humans and various species as well.
Every living thing acquires a weapon — either intelligence, strength, art, imagination, wealth.
Whatever power is assumed, it must be feared. Not to let it take over you, To control and consume you.
Power will make you weak if it consumes you.
Once power takes over somebody, he/she underestimate its influence. The potential gains on them and takes control, even though they resist and fight to regain control.
He/she gains more power consistently without noticing the fact he/she is losing control. No gains made. It could be losing it through failure in its environment, whether through external influence, from relationships, or through some physical interaction, perhaps in education. They lose power through other mental realities. Therefore they lose themselves.
Because his/her power consumes, their wears away, due to being overwhelmed. Their ability is no longer relevant with change and loss of control. Therefore, they fail and collapse.
Permanently, achieving nothing, but falling with emptiness and dissatisfaction, due to a loss of control and soul.