Typically, life is tracked on paper by creating a column for each player and doing some elementary subtraction from the totals as the game progresses
While there were already a number of tournaments out there, going so far as to have some broadcast on ESPN 2, none included that randomness that often filled Magic games
As a result, the rules implications of this ability are pretty unclear
I wouldnt recommend using the ones contained in your boosters, because each pack only contains one, so you will be short by a lot
But Soltari Champion granting all your other creatures +1/+1 is very nice, and it even stacks in multiples
While damage can still accrue if your opponent has a card with a 'damage can't be prevented' effect, that damage still can't be dealt until the Terefi's Protection has been lifted on your next turn, and your lifetotal can be adjusted again