I have fought
I live to fight

I think "I have fought // I lived in the fighting" is closer.

"this atrocious reality should not be allowed to become a routine thing."
Since it's 日常であるはずがない, it's more like "should not be a routine thing" and not "become" (the latter would be になる I think)

しかし、どうしたらそのような世界になるのか、その方法が思いつかない。
Yet, I do not understand why such a world cannot exist.
Yet, I cannot think of a way for such a world to exist
(どうしたら is more or less 怎样才能够)
(そのような世界になる → to become such a world; but it wouldn't work in English)

俺は、戦うことしかできないのに。
破壊することしかできないのに。
そんな俺に転機が訪れた。
The "のに" at the end of first two lines roughly means "even if"
"Even if I can only fight
Even if (I) can only destroy
'That' me came to a turning point"

戦いしかできない俺に、成すべきことができた。
I, who was otherwise powerless, was given the ability to fight
I who could only fight, could do/accomplish that thing (I suppose eradicate conflict??)


lmao fail jap. XD I wouldn't be able to get these if not for the already-up-there English parts. XD;