Here's what needs to be done before you can get the quest for the L75 minions:
Level 35 spell quest must be completed to get the L55 spell quest (has it's own prequest requirement) Level 55 spell quest must be completed to get the L75 spell quest*** Level 75 1st spell quest must be completed to get the 2nd L75 spell quest Level 75 2nd spell quest / 2nd Generation Minion spell
***The guides then break down into the school specific quests.
