The following give us a glimpse of the bravery and courage of Imam Husain (عليه السلام) in the battle of Karbala:

1) From Ziyarat al-Nahiyah al-Muaqaddasah as narrated to be from Imam Mahdi (عليه السلام):

فثبت للطعن والضرب، وطحنت جنود الفجار، واقتحمت قسطل الغبار، مجالدا بذي الفقار، كأنك على المختار

"Hence, you stood firm in facing the stabbing & and the striking, You crushed/destroyed the soldiers of the transgressors, and stormed (courageously) into the dust of the battle, fighting with Thulfaqar as if you were Ali (ع), the chosen one."

[Source: al-Mazar al-Kabeer - al-Mashhadi, Pg. 503]

2) From the book aL-Manaqib of Ibn Shahr Ashub: 

ثُمَّ حَمَلَ عَلَى الْمَيْمَنَةِ وَ قَالَ‌

الْمَوْتُ خَيْرٌ مِنْ رُكُوبِ الْعَارِ وَ الْعَارُ أَوْلَى مِنْ دُخُولِ النَّارِ

ثُمَّ حَمَلَ عَلَى الْمَيْسَرَةِ وَ قَالَ‌

أَنَا الْحُسَيْنُ بْنُ عَلِيٍ‌ أَحْمِي عِيَالاتِ أَبِي‌

آلَيْتُ أَنْ لَا أَنْثَنِي‌ أَمْضِي عَلَى دِينِ النَّبِيِ‌

وَ جَعَلَ يُقَاتِلُ حَتَّى قَتَلَ أَلْفاً وَ تِسْعَمِائَةٍ وَ خَمْسِينَ سِوَى الْمَجْرُوحَيْنِ فَقَالَ عُمَرُ بْنُ سَعْدٍ لِقَوْمِهِ الْوَيْلُ لَكُمْ أَ تَدْرُونَ مَنْ تُبَارِزُونَ هَذَا ابْنُ الْأَنْزَعِ الْبَطِينِ هَذَا ابْنِ قَتَّالِ الْعَرَبِ فَاحْمِلُوا عَلَيْهِ مِنْ كُلِّ جَانِبِ فَحَمَلُوا بِالطَّعْنِ مِائَةً وَ ثَمَانِينَ وَ أَرْبَعَةَ آلَافٍ بِالسِّهَامِ

Then al-Husayn (عليه السلام) attacked the right wing [of the enemy] and recited:

"Death is better than shame, But shame is better than entering the hellfire."

Then he attacked the left wing [of the enemy], reciting:

I am al-Husayn ibn Ali (عليه السلام), The defender of the family of My Father.

I have sworn never to surrender, As I travel on the path of the Prophet (صلى الله عليه وآله).

He carried on fighting until he had killed 1950 men and wounded a number of others.

Umar ibn Sad told his men, "Woe unto you! Do you know who you are fighting against? This is the son of al-Anza al-Bateen. This is the son of the killer of the Arabs. Attack him from every direction!"

Then they launched an attack on him with 180 lancers and 4000 archers.

[Source: al-Manaqib - Ibn Shahr Ashub, Vol. 4, Pg. 110]