Can Wall of Blood and Transcendence be used to gain infinite life?
Yes, that should work (with the caveat that you can never gain 'infinite' life, you have to specify an (arbitrarily large) number, how often you are going to repeat the cycle, upfront). It's important to note that you can't pay life you don't have (even with Transcedence on the field) but you've already accounted for that.

One may expect for a combination of three cards (two of which are rather bad/mediocre on their own) in three different colors to be so powerful. It's a rather risky one as well; if Nature's Claim gets countered, you'll lose the game.