I'm not familiar with DCC's Warlock rules.
I think a patron system could be easily addressed with ceremonial magic, with the "stigma of failure" simply being the disfavor of the patron when It is bothered too much or with poorly-executed rituals. You could create a custom mishap table that would be various quests/punishments from the patron. And you could give a +1/-1 bonus/penalty either to specific schools of magic related to the patron or unrelated to the patron, or circumstantially based on whether the particular act serves the patron's interests (bring about chaos vs. healing the sick etc.)
This should be an Axiom article!
Agreed that's why I was thinking of just using the exising system in the Heroic companion. Here's how it normally looks when you cast a Contact Patron spell:
And if you look you'll notice there are addition spells associated with a patron
Atraz A'Zul, Mother of Spiders
Atraz A'Zul is a spider demoness of ancient lineage whose intrigues are manifold, subtlety legendary, and cold calculation uncompromising. She is the demon spirit of dark and quiet places and the unseen things that creep there. To form a bond with Atraz A'Zul, one must go into the desert and ingest the hallucinogenic spider known as the Dream Stalker. Atraz A'Zul will appear to the dreamer who must pledge his troth to her and her alone. Those who serve the demoness are expected to protect spiders, scorpions, and other poisonous vermin.
Invoke Patron check results:
12-13 Atraz A'zul answers the petitioner’s plea, but is contemplating dissymetries in her web of control, and is distracted by other matters. The caster receives +4 to his next attack, saving throw, skill check, or spell check.
14-17 The caster’s touch becomes poisonous. For the next 1d5+CL rounds, targets touched by the caster must succeed on a DC 10+CL Fortitude or take 1d5 per round of damage for the next 1d5 rounds.
18-19 For 1d4+CL rounds, the caster takes on the aspect of a giant spider (about the same size as a mule). His AC and Ref saves improve by +2, and with a successful Will save (DC 10), the caster can draw upon the essence of Atraz A'Zul gaining 2d4 hit points. If the caster critically fails the Will save by rolling a natural 1, he must burn 1d3 each of Strength, Agility, and Stamina.
20-23 Atraz A'Zul grants the caster the ability to see the connections between strands of the web of life for 1d6 rounds, during which he is able to gain a +3 to any roll.
24-27 The caster’s weapons become venomous. For the next 1d4+CL rounds, targets struck by the caster’s weapons must succeed on a DC 10+CL Fortitude save or fall paralyzed for 1d6 turns. The magic is associated with the caster’s weapons not the caster; while the magic persists, another character may attack with these weapons to gain the same benefit.
28-29 Atraz A'Zul grants the caster the ability to see the connections between strands of the web of life for 1d6 hours, during which he is able to gain a +3 to any roll. His allies may make any roll at +1.
30-31 The caster is able to summon a 2d6+2 HD Demon Spider. For 3d3+CL rounds, the caster may command it as if he were Atraz A'Zul herself. Demon Spider Init +4; bite +8 (1d10, poison) melee or web +8 missile (special: Ref save DC 15 or bound until released); AC 18; HD 6d12; MV 40’; Act 2d20; SP darkness (+6 spell check), demon traits; SV Fort +6, Ref +8, Will +6; AL L.
32+ Atraz A'Zul recreates the caster in her image and with her powers. For 1d12+CL rounds, the caster and five allies of his choosing receive +6 to AC and all saving throws, +5 to all attack, spell check, and damage rolls, and the caster receives 2d12 additional hit points. He also takes on the aspect of a spider, and may bite, cast webs as melee weapons, and make enhanced saving throws (act as Spider Demon in result 30-31, above), and use Spider Climb and Darkness spells at-will, with no spell check.
1 – A variety of normal spiders appear when the caster casts any spell. They crawl everywhere, infest everything, and otherwise distract and annoy but otherwise do no harm. If this result is rolled a second time, the effect is amplified such that a host of spiders appears with each spell. The host is large enough to distract nearby creatures within 10’, both friend and foe (DC 8 Will save or -1 to all rolls for one round), though the caster is immune. If this result is rolled a third time, the spiders follow the caster constantly, day and night, whether he is casting spells or doing something else.
2 -- The caster is begins to grow long, stiff hairs on the outer parts of the arms and legs, shoulders, and back. These vary in color (1) Red (2) Grey (3) Orange (4) White (5) Blue (6) Other—GM picks. This may affect his ability to wear armor. If this result is rolled a second time, the caster begins to grow vestigial eyes, as a spider. These organs are not functional. If this result is rolled a third time, the caster's lower jaw begins to produce a pair of mandibles.
3 – The caster's diet begins to change. He craves insects, and begins to eat them in addition to his normal food. If this result is rolled a second time, the caster will only eat live insects or small vermin like rats, moles, or mice for sustenance. If the caster rolls this result a third time, he grows fangs and is able to poison his prey with a bite, paralyzing it (DC 13 Fort save) and dissolving the prey's innards after an hour. He may then suck out the liquefied matter.
4 – The caster becomes more reclusive, tends to use go-betweens to conduct business outside of his home. If this result is rolled a second time, the caster begins to construct his lair as would a spider, with many alarms to alert him to intruders and traps to hold them fast to be dealt with. If this result is rolled a third time, the caster grows spinnerets, and the ability to build webs. He is compelled to seek out a domicile where it is possible to build them, like an old barn or an abandoned ruin.
5 -- Whenever the caster casts a spell, his legs extend and change their joint structure. They look unsually long and thin for a period of 1d4 rounds, at which point his legs return to normal. (If a spell effect interacts with this, the spell effect takes precedent.) If this result is rolled a second time, the transformation is more complete, such that the caster’s legs truly resemble a spider’s legs for 1d4 turns. He does not gain any extraordinary climbing ability but scuttles in a way which looks strange, and grows four large bumps on his hips and torso, where a spiders legs might appear. If this result is rolled a third time, the caster’s legs permanently change into spider's legs, and the bumps sprout full-sized spider legs. He gains the ability to climb vertical surfaces at his normal movement rate.
6 -- When the caster casts a spell, tiny spiders emerge from his clothing. Then they scamper off into the shadows. If this result is rolled a second time, the spiders appear not just when the caster casts a spell but also 1d4 times randomly each day. It may be when the caster sits down to dinner, or tries to study a spellbook, or draws his dagger for combat: the spiders just appear. If this result is rolled a third time, some large and venomous spiders appear at times, and the presence of spiders becomes a permanent. They are always crawling in his vicinity and on his person.
Like I said it looks cool but seems to be a lot to convert. I like the streamlined version of ACKS so I may just fiddle with the Stigmata rules like you suggested and leave the patron part for role play.