If you dont have a super health tame, run, the fire wyvern do not burn you easily, ligthing does a lot of damage and torpor (most of the times they do not miss) and poison, they take down player damage mostly, so dont subestimate them.
The mos recommended tip is to go with a higl lvl golem or rex to kill them without problem, except poison ones, if they shoot you, get away from the cloud or youll die.
Good luck survivors 😄
If your playing by yourself or very few people all you need is a argy pumped with health, stam and melee and argy has tighter turn radius so you can fight wyverns without worrying about special attacks but in group stay in middle. Like so people can see
The best way to level up a Giga on Rag is to get a bunch of wyverns to follow you on your griffin/ptera, then dismount you’re flyer above the Giga, then get on your Giga and absolutely destroy them. This got my Giga 26 levels from 3 wyverns.