but TToD comes out before he blocks therefor he enters battle without a weapon
Nebby has not blocked until his ability completes. His ability does not complete until he grabs Swift Horses and Swift Horse's special ability has been completed.
Right. The triggered ability of TToD doesn't activate until all SA's associated with the trigger (Nebby blocking) are completed. So once Nebby blocks, gets Swift Horses, then draws two cards and plays next, there is now an evil weapon in battle, and your king doesn't get to play an enhancement via TToD.