Could someone explain the Fractured Tenrai event?

So I’m down to 2 challenges left, neither of which are event challenges. I’m on level 7, do I not get to complete the other 23 tiers?

I’m not sure exactly how it works, but it seems you are not guaranteed to have event challenges in your current challenge set. It might be like a random chance that event challenges will appear in your challenge list. So I guess you have to complete the two challenges you already have first for a chance to get new event challenges.

The event is split into 4 different weeks, so you will have to wait for the next time the event comes back to earn the next set of rewards