make the ignore a temporary only solution (3-6 months) to have a possibility to "forgive" as maybe the online social behaviour of the ignored might change over time.
make it possible to the ignored to see how many players are ignoring him/her, so he/she gets a feedback that might lead to an adjustment of his/her online behaviour to the better side.
i would like to add a few ideas for considering:
make the ignore a temporary only solution (3-6 months) to have a possibility to "forgive" as maybe the online social behaviour of the ignored might change over time.
make it possible to the ignored to see how many players are ignoring him/her, so he/she gets a feedback that might lead to an adjustment of his/her online behaviour to the better side.