His greed led to his downfall.

His reckless actions led to his own ruin.

His company fell into ruin due to the economic crisis.

We should always remember the power of Kannon in difficult times.

I decided to attend the party in response to his invitation.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.