Walt didn't care about Todd. He simply took him under his wing after Jesse quit. Walt only ever cared about Jesse and his family. Walt actually went to the compound with the intention of killing Jesse along with the Nazis. After seeing how Todd and the rest of the Neo-Nazis had treated Jesse, and feeling partly responsible for Jesse's capture; decided to save him instead. Given Todd's previously killing an innocent young boy, Andrea, torturing Jesse and forcing him into slave labour is what sealed Todd's fate. So Walt felt Jesse deserved to be the one to kill Todd.
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Walt didn't care about Todd. He simply took him under his wing after Jesse quit. Walt only ever cared about Jesse and his family. Walt actually went to the compound with the intention of killing Jesse along with the Nazis. After seeing how Todd and the rest of the Neo-Nazis had treated Jesse, and feeling partly responsible for Jesse's capture; decided to save him instead. Given Todd's previously killing an innocent young boy, Andrea, torturing Jesse and forcing him into slave labour is what sealed Todd's fate. So Walt felt Jesse deserved to be the one to kill Todd.