As always, it pays to follow Martin Juzas prerelease principles: build a smooth mana curve, respect your mana base, and dont forget the fundamentals
From a mechanical perspective, this life loss drawback is reminiscent of black cards like Phyrexian Negator or Plague Spitter, but with a redemptive twist built in
It ETBs with energy, sure, but it can convert energy to creatures without tapping, which, of course, means you can generate infinite tokens pretty easily with the other cards here
Swing with Lathril early, generate tokens, then threaten a massive life drain that hits all opponents at once
This will shine in stompy reanimator builds, or with Rakdos/Mardu +1/+1 counters synergies