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Should Giratina be part of the Palkia/Dialga legendary group in order to create a 6th legendary trio(the others being birds, dogs, golems, weather trio and the lake trio)

If so then why?
If not then why not?

Yes. The reasons are actually quite numerous, and let me list them!


For starters, Giratina, Dialga, and Palkia are already sometimes referred to as "The Dragon Trio" for the obvious reason that all three are, in fact, of the Dragon type.


Next up, all three of them have a rare secondary type. Palkia has water as his secondary type... Kingdra is the only other pokemon with that combo... meanwhile, Dialga and Giratina are Steel and Ghost, respectively. No other pokemon have the Dragon+Steel or Dragon+Ghost typings.



The similarities don't end there, though! The next rather simple similarity is their abilities ; pressure. Okay, as far as legendaries go, that's not unusual, but now we're really getting into the nitty-gritty details of why they form a trio...



Although their base stats are all different, they are all constructed out of the same 6 numbers. Each of them has a base stat of 90 (Dialga + Giratina: Speed, Palkia: HP), they each have two base stats at 100 (Dialga: HP + Special Defense, Palkia: Defense + Speed, Giratina: Attack + Special Attack), they each have two base stats at 120 (Dialga: Attack + Defense, Palkia: Attack + Special Defense, Giratina: Defense + Special Defense), and all three of them have a 150 base stat (Dialga + Palkia: Special Attack, Giratina: HP).

That, alone, is pretty damning evidence, actually, but it goes even further.


All three learn the following level-up / heartscale moves in the same, exact way:

Heartscale - Dragonbreath
Heartscale - Scary Face
Level 20 - Ancient Power
Level 30 - Dragon Claw
Level 50 - Heal Block
Level 60 - Earth Power
Level 70 - Slash
Level 90 - Aura Sphere


All three learn their signature moves at level 40:
Dialga - Roar of Time
Palkia - Spacial Rend
Giratina - Shadow Force


All three, at levels 10 and 80, learn attacks based upon their non-Dragon type
Dialga: Metal Claw, Flash Cannon
Palkia: Water Pulse, Aqua Tail
Giratina: Ominous Wind, Shadow Claw


In the cases of those two moves, one is physical and the other is special.


Unique moves for each of them...
Dialga:
-Brick Break
-Bulk Up
-Fire Blast
-Flamethrower
-Overheat
-Roar of Time
-Flash Cannon
-Iron Tail
-Metal Claw
-Blizzard
-Ice Beam
-Flash
-Trick Room
-Rock Slide
-Rock Tomb
-Sandstorm
-Stealth Rock

Palkia:
-Brick Break
-Bulk Up
-Focus Blast
-Focus Punch
-Aqua Tail
-Brine
-Surf
-Water Pulse
-Fire Blast
-Flamethrower
-Spacial Rend
-Avalanche
-Blizzard
-Hail
-Ice Beam
-Fling
-Trick Room
-Rock Slide
-Rock Tomb
-Sandstorm

Giratina:
-Silver Wind
-Defog
-Fly
-Charge Beam
-Energy Ball
-Will-O-Wisp
-Ominous Wind
-Shadow Ball
-Shadow Force
-Iron Tail
-Steel Wing
-Rock Climb
-Dark Pulse
-Payback
-Calm Mind
-Dream Eater
-Psychic


Which, of course, leaves the following moves as being learnable by all three:
aerial ace
ancientpower
aura sphere
cut
double team
draco meteor
dragon claw
dragon pulse
dragonbreath
earth power
earthquake
endure
facade
frustration
giga impact
heal block
hidden power
hyper beam
natural gift
protect
psych up
rain dance
rest
return
roar
rock smash
safeguard
scary face
secret power
shadow claw
shock wave
slash
sleep talk
stone edge
strength
substitute
sunny day
swagger
thunder
thunder wave
thunderbolt
toxic


(The only other pokemon that can learn those exact moves is Smeargle. biggrin )
(Next closest is Groudon who can learn all but 4 of those.)


I suppose you could also include as "proof" that Giratina is supposed to be the pokemon on the cover of the next Pokemon game? (IE the 4th gen equivalent to Emerald.) (I don't think this is confirmed, though. The game is only supposed to be released sometime this year in japan, I think.)




I hope you've enjoyed reading this analysis as much as I've enjoyed making it. smile

...
Err.
I disagree, Every generation comes with one trio of legendary pokemon.
G1
Arcticuno, Zapdos, Moltres
G2
Entei, Suicune, and Raikou
G3
Regirock, Regice, Registeel
G4
Uxie, Mesprit, Azelf

Most of the other legendary fit into other combinations.
G1.
Mewtwo and Mew go together. (Mew can also be categorized in a Supertype.)
G2.
Ho-oh and Lugia (However, Ho-oh fits with the Legendary beasts, and Lugia fits with the Legendary Birds) Celebi is part of a super group. (Which Mew May or may not be a part of.)
G3.
Kyogre, Groudon, and Rayquaza. Latias and Latias. Deoxys is it's own group as it has 4 forms. Lastly, Jirachi is part of the same Super group that Celebi is.
G4.
Rotom, Heatran, Cresselia, and Shayman, Darkrai have no groups.
Phione and Manaphy are a group. (Same concept as mew and mewtwo)
Arceus is in the same super group as Celebi, Jirachi, and possibly Mew
It is possible to Include Giratina, Dialga, and Palkia. However,
Dialga and Palkia fit in another Super group. (they fit with Lugia, Ho-oh, Kyogre, Groudon, and arguably Mewtwo, Mew, Latios, and Latias.) In that regard, Giratina would be categorized with Cresselia, Shayman, Darkrai, Rotom, and Heatran as the legendaries that have no grouping.