I don't believe Jungian individuation, weaknesses, or other people can truly be appreciated without an understanding of the archetypes and shadow, so here you go:

http://www.erictb.info/archetypes.html

Here's my terrible quality overview, because that link connects you to a compendium of excellence that you're just going to have to explore on your own:


-Everyone uses all 8 functions in their stack, represented by the following archetypes:

1. Hero
2. Parent
3. Child
4. Inferior
5. Warrior/Amazon
6. Witch (Crone)/Senex
7. Trickster
8. Demonic

-Some INTP-specific excerpts
Spoiler: Spoiler


INTP

Hero complex (main ego) determines what’s correct (true/false) as stimulated by individual reference (Ti)
Parent complex engages the implications of reality, stimulated by the environment (Ne)
Child complex engages tangible reality, stimulated by individual reference (Si)
inferior (Anima/animus) complex determines what’s desired (good/bad) as stimulated by the environment (Fe)
Warrior/Amazon (oppositional) complex determines what’s correct (true/false) as stimulated by the environment (Te)
Witch (Crone)/Senex complex engages the implications of reality, stimulated by individual reference (Ni)
Trickster complex engages tangible reality, stimulated by the environment (Se)
Demonic Personality complex determines what’s desired (good/bad) as stimulated by individual reference (Fi)

INTP:

Lead with Ti (hero):


Default ego worldview is to turn inward to make impersonal assessments ("correct" determinations stem from an individually learned blueprint of order). May overdo it and neglect the personal side of things and the outer world.

Support with Ne (parent):


Supply worldview with data, and tend to help others by turning outward for conceptual observations (emergent ideas of what "could be" extracted from objects in the environment). May overdo it and resist tangible reality (life "as is"), details, etc.

Find relief with Si (Puer):

Reflects aux. by turning inward for tangible observations (referencing an individual storehouse of "what is" via experience). May overdo it and become stuck in the past (in a childish way), or stubbornly cling onto what is known to be true and not change it.

Aspire to Fe (inferior/anima):

Deep down inside want to turn outward to make personal assessments (harmony or other "good" determined based directly on the group or social "environment"). May overdo it and on one hand, become too dependent on acceptance by others (neglecting any inner sense of self), yet still not be willing to adapt to social situations seen as illogical

The SHADOWS:


Oppose with Te (also backup):


When ego feels obstructed by something, turn outward to make impersonal assessments (the determination of logical, "correct" order is implicit in the object or environment).
Use this to try to beat others at their logic using their own principles.

Critical with Ni (Senex):


When ego feels negated, turn inward for conceptual observations (referencing individual less conscious impressions to infer the meanings of patterns). Parental "authority" which focuses on a lot of possibilities now locks in on one (stored inside, and previously ignored), usually reflecting the negative pattern associated with what caused the feeling of negation in the first place. It can become good if more attention is paid to such inner intuitions, in which case "big pictures" would be found, with more positive implications.

Trick with Se:

When ego feels double-bound or put upon; turn outward for tangible observations (emergent experience of "what is", in the environment) Throw facts back at people to get them off my back or reverse the expectations. Child, storing past facts and burdens, now turns "bad" and grabs emergent data against the accuser (usually what the other person is doing that is the "same thing they criticize me for"). Use of tangible contrasts and oppositions (sights, sounds, etc) can come in handy in a comical way.

Be destructive with Fi (Daimon):

When ego feels threatened with destruction; turn inward to make personal assessments (harmony or "good" is determined from an internal blueprint of "good", individually learned or from nature). When not getting the acceptance the inferior complex desires, and especially when it just doesn't make sense, as the hero(ego) desires, then there may be feelings of being "no good", totally, or that maybe even life itself is corrupt. Eventually, can draw a sense of worth from stressful feelings. It seems to involve realizing that ego (at least in this current earthy state) is temporary, and the things it wants is not really worth such feelings of destruction.