What Does Oathbreaker Do?
Oathbreaker has the Lifesteal ability, but more importantly she also buff other characters that also have Lifesteal: every time she attacks, all your Lifestealers on the battlefield gain a permanent +1/+1 buff.
That doesn't just mean that they're stronger fighters. It also means that the amount of life they steal is greater, allowing you to potentially build up a much greater pool of health.
At the time of writing it's to early to tell what the effect of this new card will be on the meta. I suspect it may well make 'vampire' decks more viable than they have been previously.
This page written for Eternal version 1.20, Card Set 1
Last updated: 15-06-2017