Or a toa with a Pakari and a Quake Breaker.
Easy solution: Be a Rahkshi of hunger.
Super-hard challenge: try and beat every map with a boss in order without ever dying. Even I can only beat the levels individually -- it takes me a few tries; each time I die, I restart. Also, a thought for the next map: a jungle (Le-Koro, Voya Nui, Bota Magna...)
Rahkshi of Camouflage with maxed-out Strength and Earth Claws is another good one, at least while we're still only dealing with 'bots.