Last Light of Durin's Day

Whenever a Mountain you control enters, put a quest counter on this enchantment. If it has six or more quest counters on it, sacrifice it. If you do, search your hand and/or library for a Dragon card and put it onto the battlefield. If you search your library this way, shuffle. Mountaincycling (, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)