This damage can accumulate extremely quickly and can often deter players from casting numerous impactful spells out of precaution of taking too much damage from Ruric Thar
The Balrog, Durins Bane costs five mana plus one black mana and one red mana in order to summon, so it works really well in a Sauron-themed deck
In this case, the card makes you sacrifice permanents when you take damage, so you dont really have life points anymore
Boil actually does see play in Modern, in the sideboards of decks like Jund and funnily enough, its an exceptional card not just against blue decks but also against things like Four-Color Omnath, where it will still blow up a ton of opposing lands
To be honest, she might do a little bit too much, especially once you flip her