Imperfect: You know that saying 'as cunning and sly as a fox' well that fits perfectly with Seru's personality in this form. He appears as being very crafty, always being very clever and devious about how he handles things. He always seems to be able to escape from any trouble he gets into, scheming up a plan to avoid the problem.
He's clever enough to realise that his main objective is to gather energy and hunt down the androids so if he is faced with more than one opponent he slinks away into the shadows.
He is very polite when he meets someone but if you tick him off he can become nasty. It's clear he has intelligence in this form and he definitely strives to get what he wants and doesn't let anything get in his way. He's cruel and sadistic, which is influenced by his appearance. He enjoys scaring people before he kills them, well when it came to the girl and the boy in the hanger he did. Maybe he likes to hear girls scream.
2nd Stage: Being half perfect has it's flaws. Not only does he not look very pretty but he also acts pretty dumb or appears to act dumb. Absorbing 17 greatly increased Seru's power boosting his ego. He lets his cockyness get the best of his decisions, getting him into to trouble. He plays around with 18 too long because he knows she has no chance against him and he likes to make women squirm (he's such a womeniser). This allows her to escape.
He underestimates Vegita, getting his ass kicked but he may appear to be stupid but he's still has his sly streak because he manages to trick Vegita into letting him absorb 18 by playing on Vegita's own ego.
So in this form he has inherited a very cocky personality but he still has all the qualities from his previous form but they are hidden because of it. He still has his polite streak and some charm shines through when he's harrasing 18. (womeniser)
Perfect, Ultimate form: Seru has now become the perfect warrior. His speed, strength, stamina and skill have all been heightened. He still has a massive ego but it doesn't get in the way of his actions, not as bad as it did in his previous form, he learnt from his mistakes.
He's handsome (stop starring at me like that, I have a right to my own opinion...so there) He is very intelligent, very polite and very charming when it comes to women (television station, he was grinning like master roshi watching a fitness class and talking about fitness classes you should see his face when the girl in the leatard was on his shoulders. *eyes Seru who's looking around with the expression 'I don't have clue about what you're talking about' written on his face*
Seru has many of the best qualities aquired from the DNA of the other fighters, adding to his personality.
Vegita: Massive ego, Saiyan strength, super saiyan ability, temper, crossing-arms pose, smirk, Gallet Gun or is it Garret?, good looks, brilliant fighting strategies, fighting streak.
Goku: Saiyan strength, super saiyan ability, huge appetite (big appetite for humans), Kamehameha wave, spirit bomb, quick calm thinking, Hair? (the split head crest could be a helmet), fighting streak.
Gohan: Saiyan strength, super saiyan ability, Loyalty/truthful (ever heard Seru lie?), intelligence.
Piccolo: meditative, intelligence, special beam cannon, lazer eyes, regeneration, thoughtful (thinks things through/reason), determination.
Tien: Solar flare, humanity (very very little humanity...but it has to be there).
Krillin: Kienzan, panicy streak (when things don't go his way), humanity.
Frieza: pale skin, ears, armour?, eye colour?, ability to survive in any enviroment, different forms, lizard feet in Imperfect form.
King Kold: Height and cool english accent (but better than Kold's, it isn't whiney or too posh its...Sexy stop looking at me like that...I mean it.
This is a point made by Masquerade (another obsessed Seru fan): Dr Gero added some of his DNA into Seru's design, they used the same tactics when hiding fron the Z fighters, running instead of flying. I hadn't noticed this. Clever Masquerade.
*Turns to Seru, 'Did he use his DNA in your design?' Seru shrugs and sees an opportunity to escape and runs for it. 'You can run Seru but you won't be able to hide from me forever.' skips off merrily in the direction he ran*