Venat is an antagonist, she's just not treated as one. Sorry, you don't get to enact racial cleansing, spare the very people you know will cause rejoinings, compromise the integrity of the planet, all the souls upon it, and tie the fate of 13 (originally) other shards to its survival and not objectively be considered an antagonist in terms of the world's history. Literally the only reason she's not is because she helps the WoL, ignoring that she put all her eggs in the WoL's basket and it's in her own self interest to ensure nothing bad happens to them. (Also ignoring that the WoL existing means she tore her protégé's soul apart not to mention condemned Ardbert.)

Having to reiterate this because apparently even after almost 700 pages it still needs to be said.

I'm not claiming she's malicious and evil either since I know that's coming next. The road to Hell is paved with good intentions. She can be well meaning and still responsible for heinous and unforgivable crimes against mankind (both unsundered and sundered) for the supposed 'greater good'. The only difference is FFXIV tried to gaslight their way out of it.