Re: Sorcerer Supreme Building
Actually, I don't find Favors/Indebtedness to really be represented in the source material. It's not like you see Doctors Strange or Fate get on the ol' magephone and say "Hey, She-Witch. Do you remember when I helped you dispatch those Sliggering Mictucrants from Oblivex III?" They scout around for a while,maybe, but eventually they're gonna kick in the door and go "I AM THE SORCEROR SUPREME! YOU MAY NOT RESPECT ME, BUT YOU'RE GONNA RESPECT MY OFFICE, JERKY!"*
Contacts are good, but I'd make sure to give them a high PRE, good Conversation, Oratory, and Persuasion skills. Trading Favors is for dabblers and up-and-comers, not for the Protector/Despot of an entire planet/dimension.
*Real dialogue may differ. Your milage may vary. Offer not valid in the Lower Planes or Ohio.