Well for the existing wars that have happened (none happening in canon now) you should know:
Tenebris war: War between heaven and hell which lasted 5,000 years and ended roughly 150 years prior to 2068.
Demechrelle: spread darkness throughout the lands some 1700 years ago, dunno if it can be considered a war tho
Dridder-Naga war: about 2,000 years prior to current date involved a large chunk of the southern territories
Elven Empire: thousands of years ago, they warred constantly throughout the middle and northern areas I think. Not too much info here, but they subsumed species into their empire instead of slaughtering them all, which let them (we surmise) not get killed by the guardians. Battles were tiny.
Corrector War: 10,000+ years ago basically tried to "re-balance" all of felarya or something, biggest war Felarya's suffered to my knowledge, and Guardians had to create the Titans and the lava elementals tagged along to win.
Ur Sagol wasn't destroyed thanks to war, and I think those are all the major war like events. Obviously the Corrector War is the biggest one, and I think it should really be the only one of its like to be honest. So personally I don't know how much I'd like an entire felarya-wide war.
You mention "beyond evil" which I take it to mean he's incredibly evil. Someone who wants to wage war would need resources, manpower, motivation, and other things to make it seem realistic, and even then, why would he want to wage war on <i> all </i> of felarya. something to consider I think...
Not to mention how. I mean, the fairies alone would be difficult to combat.