Halo needs daily,weekly and monthly challenges, yes i said monthly, with each challenge tier rising the rewards will rise as well, imaging doing a monthly challenges for 1 prophets bane and a bunch of other random single use reqs for warzone and firefight, so as the challenge tier lowers the rewards do as well, daily = bronze or silver, maybe even for 2 wasps, but the rewards need to be something good
I sure know for hells sake i would do a daily challenge for a random vehicle, and just for something small, imagine all the people that would try to do the monthly challenges