Batterskull Courser only gives one life per land made, usually just one per turn (although it does mitigate sac lands well as well as having great synergy with the shuffle!) and not always even that
Number 42 Language English Legal Formats Commander, Legacy, Pauper, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Modern, Pioneer, Standard, Timeless Rulings (10/4/2004) If you sacrifice a colorless creature, you get to see their hand but they discard no cards
Attaching an Equipment to a creature you don't control by using a shackle ability doesn't cause that Equipment to change controllers
On top of giving near immunity to counters, red and black have a ton of creature and artifact removal effects, and with Shadow giving them split second, you can get around most tricks that other colors can use to protect their permanents
As with other siege battles, one of your opponents will 'defend' the battle, and you remove counters from it to defeat it by dealing damage to it, just like attacking a Planeswalker