This riddle describes me. Who am I?

It's not possible to drink my first three,

But possible to drink my first four.

My last four are meaningless, it seems,

Unless their meaning is sure.

I have the perfect number of letters,

My powers can destroy once and for all.

Am I real? In a way, you see,

Just don't place your hopes on a ball.

Who am I?

Notes:

• It's a proper drink! If you're thinking of Rocket, for example, and trying to link "Rock" to "Rockstar Energy Drinks" or whatever... you're going way too far.

A possibility:

SOURCE

It's not possible to drink my first three,


You can't drink a sou - it's a small copper coin.

But possible to drink my first four.


You can drink a whiskey sour

My last four are meaningless, it seems,


urce isn't a word

Unless their meaning is sure.


... but it is the name of the planet which, "During the height of the Galactic Empire's New Order, ... was the seat of Imperial power".

I have the perfect number of letters,


6 is a perfect number, equal to the sum of its own proper divisors (1+2+3=6)

My powers can destroy once and for all.


In The Matrix universe, the Source is where obsolete programs go to be destroyed. When "The One" returns to the Source, Zion and the Matrix are destroyed completely and the cycle started anew. The source of the Prime Program that makes "the One" the One also had the power to destroy Agent Smith once and for all.

Am I real? In a way, you see,


Artificial Reality of the Matrix

Just don't place your hopes on a ball.


Not sure. Perhaps a reference to the Death Star, from the "Urce" Star Wars reference.

• Wow, this one was really good. A tad far-fetched, and not what I had in mind, though I'll accept out of the sheer thoughts put behind this. Commented Jul 17, 2017 at 12:04

Well, I think I've got an answer.

The word is BOMBER.

As the first line suggests,

It is not possible to drink the first three letters, but the first four makes it BOMB, and yes one can definitely drink a Bomb Shot.

The last four are quite meaningless as in

the letters MBER

It says ' I have the perfect number of letters. '

And well, BOMBER has 6 letters, and 6 is definitely a perfect number (the sum of its divisors being equal to the number itself) .

As it then says:

The powers of a bomber (aircraft) can definitely destroy things for once and all.

And finally,

It IS real in way, and the 'just don't place your hopes on a ball' clearly indicates to the bomber ball, that is a toy for pets ( usually dogs ), and well it's performance coefficient is certainly not very high.

And that's it, I guess.

• This is not what I had in mind, in fact! BOMBER is quite smart; however, does it explain the fourth sentence? ...unless their meaning is sure. Commented Jul 15, 2017 at 6:22

It's not possible to drink my first three:

Ato

But possible to drink my first four:

Atom drink

My last four are meaningless, it seems, Unless their meaning is sure:

omic meaningless
but omics informally refers to a field of study in biology ending in -omics, such as genomics, proteomics or metabolomics.

I have the perfect number of letters:

6 six characters perfect number 1+2+3=6

My powers can destroy once and for all:

Atomic Bomb power can destroy all.

Am I real? In a way, you see, Just don't place your hopes on a ball:

Atomic Fire balls (spicy)

Atomic

• Hmm... this seems like a serious stretch, and isn't what I had in mind either :) Commented Jul 16, 2017 at 23:57

BEERUS - a fictional character in the Dragon Ball universe, Beerus is the God of Destruction of Universe 7.

It's not possible to drink my first three:

How do you drink a bee?

But possible to drink my first four:

Indeed; however, moderation should be exercised :)

My last four are meaningless, it seems:

erus ... ???

Unless their meaning is sure:

Flip it around, you get sure.

I have the perfect number of letters:

6 is a perfect number.

My powers can destroy once and for all:

Beerus usually uses his power to destroy planets, but he is strong enough to destroy entire solar systems with ease (as said by Whis when describing Beerus' might when angered).

Am I real? In a way, you see:

Beerus is a fictional character, so he's "real" in a way.

Just don't place your hopes on a ball:

The series revolves around the collection of "dragon balls". They are orange, crystalline spheres with the ability to call forth the Eternal Dragon who can grant wishes to anyone who gathers all seven of them. (placing your hopes on a ball)