By my calculations, this would be the 4th time dying (the third time I didn't know it counted since it was mirror!asgard and dying was a way to get out of there, my apologies!).

As for the permanent consequence, i was thinking to have Kaworu's core exposed permanently. Kaworu's core is fused to his sternum and covered with skin and some fat, so it's not seen; my idea would be for it to be showing like how it happens with his siblings/progeny in canon

http://animeveryday.files.wordpress.com/2011/11/vlcsnap-2011-11-24-09h21m43s203.jpg (the red ball thing)

would that be feasible?