Here is the Dark Portal from the last mission in Alliance campaign.It is guarded by demons, but reaching this point, where the round island under it is occupied, the portal will easily fall. However, reaching this point is not that easy without cheats. The hardest part is to secure an oil platform. The starting oil will be enough for only one Elven Destroyer, or for the Town Hall upgrade. All the oil wells are already used by the Horde, so one Destroyer will do nothing. The best solution remain to upgrade the Town Hall and produce Mages, then cast Fire Ball and Blizzard all the time. When at least one oil well is secured, victory will not be far.