After looking more at what peoples concerns are regarding flight in the game i think I have some ideas on how I would implement it.

1. tie obtaining a wyvern to the guilds

2. Implement some sort of system or activity  that will over time earn players within the guilds a wyvern each member turning something in to get thier very own wyvern

3. (Saw this in another post and love this idea)

Horses from the horse market aka a reason to buy horses again  can be used to feed wyverns and increase thier stats over time

4. Later down the line add more unique versions of these wyverns available for exclusive pvp variants  just like the lightning horse we have now. As well as others obtained from the enhancing system with pity.

5. Node wars and siege will disable wyverns from being used as they obviously break the mode.

Concerns:

Exclusivity for something so new as flying. You cannot lock flight as a system  behind the top 1% of pvp guilds you cannot do it. It will hurt the game. Instead let everyone get flight  but give a pvp exclusive version to those that work hard in pvp

Pvpers want an exclusive version that could be the one

that breaths fire in war of roses for example.

Horses will become irrelevant:  this one is a concern but at least how it's in game now the wyvern is very situational to use  in order to best a horse and that extreme mountains like in loml  and dreigan  outside of those 2 spots wyverns  are beaten out by horses.

Dragons will replace boats:  No they have stam but also don't have cannons nor can carry crazy ammount of trade goods.

I think this would be a good way to implement it and appease most current bdo players .