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Ghazghull Thraka- 225
-3 Power Klaw
-Kustom Mega Blasta
That's way too many grots. I wouldn't run more than 2 squads of 10-19. You need boyz with powerklaws in order to run an effective horde at that point level.
The burnas and nobz need transports, or else they have no chance of being effective. Also, Nobz really won't be effective unless they're run like this: 6-8 with 2-3 powerklaws, painboy, cybork, waaaaugh banner, bosspole, 1-3 combi scorchas (on the nobz w/powerklaws), and a transport. Otherwise, you're better off just using normal boyz.
I'd also consider splitting the unit of lootas into two smaller lootas. You can run the nobz as a troop choice to free up the elite slot.
The Killa Kans are fine the way they are. That's exactly how I always use them.
What the list really needs is a little more speed, to help counter-act your opponent's moves. A vehicle or two for the nobz/burnas, and perhaps a unit of warbikes, warbuggies or deffkoptas would do the trick.
In any case, good luck!
"Any job worth doing, is worth doing with a powerklaw."
i just started playing 40k and i was thinking of running something simialar due to the fact that grotz are so cheap 2 buy. but idk. i might get more boyz first.