Hello
I'll try to answer your questions so that everything is clear after.
1. How many different buffer classes can be transferred to a character? Is there a maximum?
As my instructions say you can Transfer buffs from your mainclass and 2 other subclasses to 1 subclass. So ist limited to 4 buffer characters which can be combined into 1. Let me give you an example:
1) Mainclass: Overlord
2) Subclass I: Swordsinger
3) Subclass II: Bladedancer
4) Subclass III: Prophet
Now in the first stept you decide which of the 3 subclasses is the one that gets all the buffs. Basically, it doesn't matter. If you Chose Subclass I, you can Transfer all buffs you want from Subclass II, Subclass III and your mainclass to your Subclass I. You CANNOT Transfer buffs to your mainclass due to the olympic games.
2. Can I get buffs transferred from subclasses, or only from other characters main classes? For example, can I get buffer transfer from a character's 3rd subclass?
Yes you can get buffs transferred from subclass. The whole Transfer is only available for the scheme as pointed out above. You CANNOT Transfer buffs from mainclasses to other mainclasses. All subclasses must be on the same character (see above).
3. What is the maximum level of buffer that can get transferred? Do I get buffs that I learned until level 80, or can I get Counter Critical or Dance of the Berserker (which are level 83 buffs) for example?
Since you Transfer buffs on one side from your subclasses, you can only get buffs that you have learned, ie until Level 80. On the other Hand, you can Transfer buffs from your mainclass that you learned, ie until Level 85.
It's you who decides when doing that Transfer. If you feel it's necessary to do it before your main reached 85 or before your subclasses reached 80 you can do it. But you will certain loose buffs. I can only Transfer buffs that you have already learnt. If the Transfer is done with Level 75 subclasses for instance and you later Level up your subclass I cannot Transfer it again. So make sure to first Level up all characters to their Maximum Level so that you won't lose buffs.
