Find it hard to believe that just because you drained the battery that you killed it, ESPECIALLY an Odessey, those are designed to last a VERY long time under extreme conditions! My 9 year old Odessey in my 1st gen is still good even though it just sets in the bike and the bike has set in the garage since '09!
You need to charge the battery at a fairly low rate for many hours, like at 2 to 5 amps for about 8 hrs. Did you check the voltage before and after charging with a voltmeter?? The reason I ask is maybe, just maybe the switch contacts for your ignition switch have gone bad. Ignition switches on 2nd gens is a weak point, and when they go, the bike is seemingly dead, no dash, no nothing, EXCEPT the radio which works on the ACC position which is a separate set of contacts.
If you put a set of jumper cables on the battery from your car/truck does the dash light up?? Once again you need to read with a voltmeter what exactly is going on...