Whats more, you gain half X life and draw the other half from your deck
Before we get into the meat of the discussion, lets look at the spoiler that really got it going
Elspeth and Underworld Rage-Hound have clear potential applications as attrition winners, but they require a nontrivial amount of cards and extra mana, restricting their ease of use outside of fairly long games
P/T Number 882 Language English Legal Formats Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pauper, Pioneer, Timeless, Vintage Not Legal Formats Alchemy, Standard Rulings (7/1/2013) If Striking Sliver leaves the battlefield after Sliver creatures you control have dealt first-strike damage but before regular combat damage, those Slivers won't deal regular combat damage (unless they have double strike for some reason)