For Bellenar, I might suggest some kind of hippy naturalists, concerned with preservation.  I don't know if lands come in to play, but I would have their mechanic relate directly to them.  

Mechanic suggestions:

Preserve: Sacrifice a non-land permanent: untap target land.  

Or:

When [i]Y[/i] Preserve [i]X[/i](untap [i]X[/i] lands).  So an example would be "When this creature deals combat damage to a player, Preserve 2.  

Could instead pull lands(possibly tapped, depending on how powerful we want it to be) from the library.  Flavor wise, the graveyard would make more sense, but it only makes sense if there's a reasonable chance that lands will get into the graveyard in the first place.  Maybe they mill themselves, and then get to take lands they find?

Just some ideas.  

Actually, I really like that last one, flavor wise.  They sacrifice their own gain in favor of lands.  

So it would go like 

Preserve X [i](Reveal the top X cards from your library.  Put all lands revealed this way into your hand, and the rest into your graveyard)[/i]