For that price, you gain life equal to the number of creature cards in your graveyard
On entry, everyone discards a card, but you refill your hand based on variety
For other purposes, however, if a card refers to your commander, it means either the legendary creature or the legendary Background enchantment
Cards with basic landcycling can get Plains, Island, Swamp, Mountain, Forest, or Wastes, plus their snow-covered land counterparts
Theres a lot of sacrifice fodder available to throw -1/-1 counters around, and the proliferate ability can help you to speed up sagas, kill bigger creatures with the previous ability, and grow some of your own creatures
In practice, it isnt that hard to play them both together because you can usually find a third colored source to get it onto the battlefield, or enough pips early to use Nykthos for three colored mana, or else its just powerful enough with the three extra pips to be worth that minor inconvenience