Indian Emperor Ashoka waged war to subjugate Kalingana. After he witnessed the destruction that the war brought, it is said that he felt extremely remorseful. It is also said that because of this war, he converted from Hinduism to Buddhism and vowed to never bring such destruction again. His conversion allowed a widespread conversion from Hinduism to Buddhism in India and its surroundings.

When it comes to Buddhist doctrine, generally violence in any form is against the Buddhist doctrine. But also in some sutras there are examples that would justify violence as well. Below is a story that is widely told when one studies Buddhism:

"The Upayakausalya Sutra tells the story of one of the Buddha’s former lives, where he is captaining a ship carrying five hundred merchants. One night, ocean deities come to him in a dream and identify one of the passengers as a bandit who is planning on killing the merchants. Buddha evaluates three possible actions: do nothing and allow the bandit to kill everyone; inform the merchants, who would kill the bandit and incur evil karma for murder; or kill the bandit himself.

The Buddha dwells on this ethical dilemma for seven days, trying to decide who should be murdered—apparently just locking up the bandit was not an option—and eventually decides to murder the bandit himself. In keeping with the principle of compassion, this is framed not as retribution for evil, but as compassionately sparing the bandit the horrible karmic consequences of mass murder, and allowing him to be subsequently reborn in paradise."

With a few short examples, I wanted to toss the discussion to this question and I am also interested, if there was any violence by using Buddhist sutras as an example. I can easily see the usage of the above mentioned " violence for a greater good" to be distorted and used for political reasons.

I don't know about China or India (or other predominantly Buddhist areas), but in Japan Buddhism being used for violence is characteristic of its history. You brought up the Ikko Ikki example, which is good, but that was more so fundamentally peasants in the Kinai provinces (those surrounding the capital Heian, modern day Kyoto) trying to break away from their lords' influence, and they had a unifying Buddhist doctrine. The Ikko Ikki revolts were in the 16th century, but Buddhism had been used for violence since its adoption in Japan in the 6th century.

At the time of Buddhism's introduction, Japanese rulers were already utilizing Shinto, the native religion, to control their people. Buddhism had entered Japan but was not a state religion. The Soga clan, a clan with political power, promoted the adoption of Buddhism as a state religion, citing the success of Chinese emperors with it. Basically they wanted also as a way to unify and control their people. But many were opposed to it. This is because the opposing clans were native and didn't want to anger native gods while the members of the Soga clan had Chinese ancestry. In the end they all killed each other until the Soga clan rose victorious and oversaw the adoption of Buddhism as the state religion. But interestingly enough, they only used Buddhism in their own estates to benefit themselves and give the clan more prestige. This went on until the empress decided they were giving themselves too much power and directed a coup d'état to depose the Soga clan from their powerful political position and to make Buddhism a true state religion. So I guess it makes sense that since Buddhism had a violent introduction in Japan with heavily political intentions that this trend would continue throughout its history.

The Buddhist churches of the Heian period were notorious for fighting each other and attacking the imperial palace. They functioned so politically because the churches were given lots of tax-free land, so they developed armies composed of the people that went to the church in order to protect their interests and fight other sects or the emperor to gain more wealth. This was a time of imperial weakness, and the Buddhist sects knew they could take advantage of it. One sect would often go ransack the capital when it gave its competing sect an advantage. The Buddhists would win with their religious influence. Often imperial armies were afraid to attack the Buddhist army for fear of divine retribution. One interesting tactic the Buddhists used was to just have two monks bring down a palanquin to the capital and set it on the ground and walk away. It was claimed that the palanquin was sacred and housed the spirit of a deity and the longer it stayed in the capital, the angrier it would get. Buddhists could often get the government to concede to their demands through this tactic.

Source:

Cambridge History of Japan