I can't understate - that if your monster box can clear sea god of heaven you'll have a hard time doing any other dungeons. Mystic Mask invades save you an unbelievable amount of stamina over time (fuck the mask dungeon even on 2x). Additionally you get between 6k/7.3k xp for 15 stamina, and metal king invades are actually a very useful +xp invade. On the weekends ocean of heaven is 1.5x drops, its 10 rounds, often you pull in 7-8 monster drops. An occasional Mystic and occasional King are pure bonus. If you feed to color 8 drops from ocean is probably very close to 20,000 xp to color (blue/light) and coin wise you loot 33/43k / run which makes it a flat conversion/coin xp to get anything to level 50. My new account is on day 68, I've been lazy here and there about wasted stamina, but my account is now rank 108. I can still rank up daily. I could use vampire skill ups, but lightless devil for my monster box is wickedly slow, and the exp is garbage. I figure I'll just wait until poring tower comes back on its once a year cycle and run till my eyes bleed, It just doesn't compare to the overall value.