I think all those cards they made into donations should be removed entirely. >_> Those cards are, in general, completely over powered. Think of all the classes that rely on buffs in order to function--Rangers, Royal Guards, Rune Knights, Shura, to name a few--who are completely done in by Valk Randgris cards. Then consider how threatening a Thanatos Card can be on a server where 550 vit is the norm. Now consider how self-destroying it is to have a Katheryn Card to pierce all MDEF only to have it reflected back at you by tons of magic reflect cards, or how devastating three Kiel cards can be, allowing users to spam otherwise subdued skills at ridiculous rates. These cards are bad news bears and shouldn't be functional on Super High Rate servers, or, if at all, they should be available to everyone, not just those with real life money.
To also offer a suggestion, perhaps adding custom headgears instead would pull in as much donation funds, and would keep classes balanced as well. Don't add crazy skills or stats to the items, that'd unnecessary; just make them fashionable and desirable and people will donate.