Super numbers

$12345678^9 \equiv 8^9 \equiv {\left(-2\right)}^9 \equiv -512 \equiv -2 \equiv 8$ (mod 10)

its obvious that 12345678MOD10 will be 8. then 8^9MOD 10=8^(9MOD4)=8 because 4 is cycle city 0f 8. so answer is 8.

Just calculate the last digit of $12345678^{9}$ and it is $8$ so our answer will be $8$ .

I agree with @Kartik Sharma I thing the problem is overrated, but here is my solution:

Lets see, ${ 12345678 }^{ 9 }\equiv { 8 }^{ 9 }\quad mod\quad 10$ . Now, we know $8={ 2 }^{ 3 }$ so ${ 8 }^{ 9 }={ 2 }^{ 27 }\equiv { 2 }^{ 7 }$ . Finally, the answer is $2^{ 7 }=128\equiv \boxed { 8 } \quad mod\quad 10$ .

Level 4????????? Overrated!!!!! Well, should I need to write a solution?

my bulky approach was: $8^2 \equiv 4 \rightarrow 8^4 \equiv 4*4 \equiv 6 \rightarrow 8^8 \equiv 6*6 \equiv 6 \rightarrow 8^9 \equiv 6*8 \equiv 8$ (mod 10)

8^9= ....728. 728 mod 10 = 8 .