It is worth noting that while under the effects of Sacrifice, your kill streak multiplier does not reset over time. Use Sacrifice 1 or 2 to carry a large multiplier between engagements, i.e. between Control Point defense waves.
"This Logos ability puts a large weapon damage buff on the user while at the same time damaging the user's health and making it impossible to regain Health by any means. Higher pump levels grant larger damage bonuses, and cost more Power to activate. Does not interfere with Body Armor repair or regeneration. This ability has an open-ended duration; activate it again to turn it off."