Lucky board is by far the best F2p event. what i mean is what you will get with respect to what you spend is actually pretty decent... lets say you spin the dice 10 times with 200 coupons and got a rare summon fragment and a seal scroll and a summon scroll and 5 coupons and some charms fragments and a medium refine rune and a pack with level 4 magatama... this is about 600 or more worth...that mean you have a discount of 60% on those items. and this is what you get normally when spinning 10 rolls.. on top of that you get between 60 to 75 points to redeem good items .. some good ninja fragments are there for 85 points so add that to the 600 worth coupons materials.

What other event gives you that??

Basically all events depend on what you need. lucky board gives you a raise in power through magatamas and give free scrolls and charm fragments and you can u*se your points to redeem rare ninja fragmnets too. so i guess it is the best event to invest in generally for all players and particularly for F2p.