Some basic questions have been nagging at me. Assistance would be appreciated 
(1) How long does a totem of revelation last, after it has been put down ?
(2) Rook - How long does a tower (using power of the tower skill) last, assuming no one attacks it ?
(3) Oak - How long does a raise dead ward last ? Is there anyway to target a raise dead ward ?
(4) How does Erebus' conversion ability work (to create nighwalker minions) ?
(a) Does the conversion ability only work on enemy creeps which are killed (or can nightwalker be created from friendly creeps killed by the enemies also) ?
(
Does the conversion ability work only when Erebus is in the vincinity ? For example, if Erebus already has some nightwalker minions. Erebus sends the minions to lane 2, while Erebus stays in lane 1. If the minions kill creeps in lane 2, do those killed creeps have a chance to convert into nightwalkers, even if Erebus isn't in the vincinity ?
Thanks in advance for any helpful replies.