Conflict between good and evil

I am looking for a large scale fight between good and evil:

• The sides aren't clearly defined. There can be good people who fight for the evil side because they have a reason or some who use any method to win despite being on the good side etc. you get it.
• The evil side may be the aggressor but they do have a reason for their actions. If possible something more reasonable than being evil for the sake of being evil.
• There are absurdly strong forces on both sides. Strong enough to wipe the floor with 'normal' strong opponents. Whether that be people, technology, or something else is not important as long as it exists AND actually gets used more than once.
• The conflict is already going on at the start of the series.
• Strategic depth whenever the forces clash with each other.

Optional:

• Clearly defined important people on both sides that heavily influence the tide for either side. Also the other side mostly knows about their importance.
• Not just focus on one MC but several (on both sides) that are somewhat independent from each other or at least walk a different path than the others even if they have the same goal in mind.

Conflict between good and evil