Tattoo Seal: Overwhelming Pain
It has all the strength of an actual lightning bolt, but only causes pain? Alt, you do realize that that much electricity over the course of even a MAXIMUM of several seconds of activation would kill a human. So yeah, change that description and state that it just causes pain and allows you to "puppet," the victim. It'll still hurt both of you, but now it won't logically kill either.
Tattoo Seal: System Shock
You might want to establish what his base and current "life span," is meant to be. If you're going to use the whole "it saps months of his lie," paradigm, then it needs to be quantifiable.
Tattoo Seal: Alpha and Omega:
Tattoo Seal: Alpha and Omega is by far Jaakuna’s most strongest jutsu he has ever created/learned.
Ehteral blue and white, two seals appear, both of circular shape:
it’s enough to completely stop his heart in an instnat
Grammar sin counter: 2. Please edit these.
You mean 'Ethereal'.'instant'.Also I see you using apostrophes wrong =_=
Lightning Release: Wave of Inspiration
This technique also requires water release, which Jaakuna doesn't have.
Lightning Release: Shadow Clone Technique
Naruto was only able to make so many NORMAL shadow clones because he was both an Uzumaki AND a Jinchuuriki. Jaakuna is neither of these things and you stated his chakra was only "moderately large." Which I take as meaning "Between 'above average,' and 'large chakra reserves.'" So yeah, making 30 would probably just tire you out completely. I'll allow a total of 10 in a given battle and maintaining more than 4 at once is a no-no.
Lightning Travels: Pulse Lightning
Unless he charges the technique before release, it will expand outwards from him at 2 meters per second (that's 6 feet) and its maximum size should be a 10 meter radius (that's 20 meters diameter, which is 60 feet).
Lightning Travels: Electrostatic
When separated from the user, the effected object will lose its charge after it has been separated for X amount of time. The time can depend on how much chakra he puts into the weapon. If he puts, say, .5% of his chakra into it, it'd probably last maybe 1 minute. So 2 minutes per 1% of his total chakra pool.
Inochiryoku no Shohi: Electical Sickle
How many crescents are released, you said "a few," that's too vague. Also, how long does the "temporary paralysis," last for the average shinobi? Given the rank of the technique I'd say 3-12 seconds depending on chakra control and other factors sounds reasonable.
Inochiryoku no Shohi: Shocking Fissure Stream
How fast does it move through the ground?
His various tattoos act as a lightning rod as they absorb and replenish his chakra.
Mmm, electrical and lightning based attacks won't be a 1:1 exchange. Meaning that X amount of lightning will not give him the same amount of chakra due to the potency difference.
Different rank lightning techniques that hit would give him different amounts of chakra, so you'd do well to figure out how much chakra. I'd say that a D rank technique would give him about .5% of his chakra back. A C ranked technique would probably give him 1.5% of his chakra back. A B rank technique would probably give him about 9% of his chakra back. An A rank technique would give him 18-22% of his chakra back. An S rank technique would give him 50% of his chakra back.