How does reward be given in World Boss?

I feel like wasting my time raiding world boss. Is the player who actually kills the boss will be the only one who gets a reward? Or the reward also go by rank of damage and will be given at end of cycle?
Can someone clear my understanding.

the one who actually kills the boss will get 1 chest immediately and if you reach a high rank or deal enough damages you can also get some chests.
here is a table from Chinese forum:

the one who actually kills the boss will get 1 chest immediately and if you get a high rank or deal enough damages you can also get some chests.
here is a table from Chinese forum:

层级=floor
名次=rank
奖励=reward
第二层~第五层=floor2~floor5
挑战宝箱=world boss chest
银币=money
以上=above

Thx for the info but until now I still get any reward.

the one who actually kills the boss will get 1 chest immediately and if you reach a high rank or deal enough damages you can also get some chests.
here is a table from Chinese forum:

I killed the boss (last hit) but they gave me nothing.