Hello!
The main idea of this Tournament is to increase cooperation between League members.
It gives several types of rewards:
1. Personal - gives when you kill the Undead.
2. Milestone Reward.
It's given after you successfully cleared a milestone floor. To get this reward you need to kill at least one Undead during this Milestone.
3. Special League Reward.
It's given when you pass Level 30, 50 and 100.
To get this reward you need to kill at least one Undead till you reach the milestone level.
Several points to consider:
1. To pass the maximum Floor you will need a lot of time as it requires the most powerful Champions.
2. Receive a reward is quite easy. The most difficult part of this Tournament is to organize your League in such a way that everyone could take a part.
The more often you'll take part in the Tower event, the more experience you will get.
For me, this Event is a good chance to get additional free reward without any great efforts.