I am sorry but I have to say this. While it is an unjustifiable cause that Ragnarok had to suffer for one FC to purchase entire ward, they had done NOTHING to violate the rules. Ethic and Rules don't apply in this game. Get that in your head.
I think you are misunderstanding the difference between new policy set on new purchasers vs grandfathered owners. And also owning multiple houses isn't against the rules. It's programmed to PREVENT new purchasers. Not in ToS. House Flipping -IS- however against ToS. I think we need to have that cleared up for you.
Grandfathering was never against a rule policy. Not in new 4.2 housing rules. It CLEARLY says "you can relocate without timer cooldown". Which means people who owned the plots BEFORE can relocate as grandfathering and give the FC that they owned to a lvl 1 alt without penalty. The policy ALSO says that ANY houses that were owned before are not taken away and for theirs to keep. You know what that means? The Mateus's infamous Ward 12 Goblet by two players are for theirs to keep with level 1 alts owning FC houses. It's not against the rules.
No one did RMT and no one definitely did house flipping. You want to report the player? Go to Ragnarok and file a report. Like every GMs tell you. Don't rant in here in this thread about how unjustified it is. The ONLY thing that will be settled in this board is if you request maybe more wards, or even more housing function. NOT rant about how it is unfair about level 1 owning the house and selling it. But I can tell you that GMs won't be able to ban someone from the source outside of the game logs. You could literally bait that player to buy it and try to talk the person in-game chat and report him.
The only way for grandfathers to give up their plot is either they in-game talk about house flipping and is caught in public or other players, OR they accidentally didnt visit their house within 40 days to refresh it and auto-demolish the plot.
That's the only TWO options there. GMs can't do anything else.