I've heard a few times that Life Siphon decks are pretty bad, whilst UD Bleed is supposed to be very good. Could someone explain what makes Bleed so much better as a strategy than Life Siphon?
Synergy. You can give bloodied in several ways: equip, champ, spell and if I recall correctly even fleshgrinder should give bloodied, and (ab)use it in several ways: bloodlust, bloodseeker, relocate bloodball, blood magic. for life siphon you need a champ that was not one rounded and not left burried under CC to do his thing to safe himself. a champ on it's own with life siphon can do well, but a full bg with it is not necessary and even counterproductive.