i love this new types of expiring building as i am fighter but i really hope developers reconsider other options with this buildings.
If you take into account how much time and efford and luck we will need to get it and then once build its useless after 5 days and next similar event will be half year from now its just not worth it for me. Having 1 day buff and give it 6 days cooldowns to activate it again so it can be used more then once in tournaments for 5th and 6th round. In my opinion that 5 days is wasted potential from that building. Another problem with this buff is that stupid AI can easily overcome this buffs and in the end some players wont see big difference in autocombat.