Intent to grief the person he was impersonating. Trying to make me think somebody else was calling me names.
And yes. Any given ban has the possibility of an unban appeal barring extreme situations like a lot of prior bans on your record. In many cases an unban still might not be granted, but that is left to the discretion of the admin issuing the ban. (typically things like how the offender responds to being banned and what they say in their ban request are considered along with past history, and we try to determine whether there's any indication that they might or might not continue to break the rules - it is not a science)
In this case, I knew Lemon had caused trouble before so the showy 356 days (the highest number you can fill in the duration boxes with) was to emphasize the fact that we (the admin team) were paying attention. As it turned out we weren't paying enough attention, I guess.
tl;dr - The initial ban was long because I knew he was a troublemaker, but the plan was not to make it permanent; not, in particular, because of what the initial ban was issued for (in terms of cRPG servers, relatively mild chat abuse/griefing).