Blank is half Blood Nui and had to get medications early on in his life to become a "full blooded" Blood Nui so his BN cells wouldnt digest his normal Nui cells. He was bullied alot for his appearance making him and his sister ( also half blood ) leaving the tribe. Blanks sister died at an early age due to the medication not working on her. After her death he became a vagabond wandering through the lands of Magandua building shelter wherever he stayed, for other travellers to get some rest as well. In Acron he found a hidden Nui city which he tolerated. He had to stay far away from the city due to Nui's being very afraid of the Blood Nui's.
Blank is very mistrustfull of others and it takes a lot of time to really gain his trust and loyalty. He is also one of the very calm ones ,thinking through everything he does to make sure not to cause any trouble.