Jiraiya
1. Jiraiya taught Pain
2. Jiraiya taught Minato which lead to Obito
3. Refuse to be hokage
4. Wasn't around to stop 9 tails attack on the village
5. Could not stop Orchimaru when he attacked the village or when he left
6. Who did he beat in a battle? ( lost to hanzo and pain)
1. nagato revived his victims. (village still destroyed , jin still dead due to him being manipulated) so touchè
2. well if you're using that logic this all goes back to tobirama, who taught hiruzen who taught jman.
3. he felt he wasn't fit, and you obviously agree (see your own number 6)
4. there were TWO kage there, tends to create a feeling of security in leaving.
5. again, that goes back to hiruzen.
**jiraiya taught naruto, he shall be redeemed.
EDIT: i'd say hiruzen. he could've stopped oro when he had the chance. been more stern than he was, which would've prevented danzo having to be and ordering itachi to do what he did i guess.