In the original timeline Lugo saved Jules, Urist & Skip from certain death at the Rusty Cave in the Goldvale area, after “The Party” returned from the Havenspass region and was starting to venture the local Goldvale area again. He'd told them Skip had gone a few days prior on rumor of their being gold in the cave, which was true. This was enough to get everyone there, but unfortunately they were not up to the challenge without an assist. Rather than perish, the three signed contracts with Lugo just before death, fine print unread, and were pulled out of the dungeon by Lugo's magical means. The terms are as follows, and they create a pending issues for our heroes in the campaign.
Due to the Nephele Timeline Branch Event the above notes about there being contracts with Jules, Urist and Skip became invalid. Instead because The Party never tried to rescue Skip, he alone was ultimately saved from the Rusty Cave by Lugo and is the only one with the contract in the newly branched timeline. Likewise Lugo is likely not aware that there was another timeline or that he'd gotten Jules & Urist to sign anything, so their contracts became invalid.
Lugo's Purple Potion was noted as a “purple potion that bubbles inside of a small glass vial” when first encountered, which was when Lugo gave it to Jules and said it would make her life “more interesting.” Many months passed with Jules pondering what this potion was for, and eventually when in a deadly scenario8) she finally drank it. It turned her from an elf, into a tiefling with direct lineage to Lugo. Because it was consumed during this particular scenario, the potion was restored as if it was never drunk, but Jules and The Party at least knew more about it from this.
At a later time Jules read Kelthor's Book Of Great Awareness and discovered another twist to this potion. It supposedly “gives her an exit strategy against even death.” To Jules who is obsessed with escaping hostile situations and never dying, this is relevant. Interesting while reading the same book, the same knowledge was given to Phoebe Nephele.
The Crompse Causal Loop largely elaborates on “Uncle Lugo's” role in Jules' life. In this loop Lugo essentially manipulates events over a few thousand years to bring Jules to the past, tying her family history to his, and ruining Skip's life while at it. Lugo's role in the loop is one of being magically bound to Skip and needing to win a bet to escape that bond, which for this character would basically represent eternal enslavement if he didn't pull it off. These relevant things happen as a result:
As promised, Wyrd Uncle Lugo goes to Havenspass and delivers the letter Jules wrote for Kess. This is the first time Lugo officially meets both Kess and her wife Nix. It is probably safe to assume that Lugo is used to these sort of odd reunions, but it might have been a little, or a lot more awkward for Jules' Moms to discover that the family tree has such a unique set of branches.
This visit to Havenspass would have been otherwise fine, had not The Party managed to enter Krymec's Vault and use it to transport themselves across continents instantly to the Havenspass region. This caught Lugo's attention and in a very short span of time everyone was reunited. Lugo then introduced Jules and friends to Simp The Imp as her Wyrd Step Cousin.
Whilst Lugo personally seemed to be amicably hanging out in Havenspass, even getting on with Jules' Moms, it didn't go so smooth for Simp The Imp. Jules grew suspicious of him and left him to die in a dungeon, which was preventable. Later she played it off to Lugo by retelling events as if Simp had died a hero trying to save The Party.
Lugo, saddened, said his goodbyes and said he had to leave town to do some soul searching and inform “the family.”
Later, after “The Party” returned to Goldvale and encountered Lugo again, Jules made Lugo promise to check up on her moms since she was no longer in that part of the world and the problematic Fauxbe was running loose there. He agreed, although didn't specify the means.