Question

Nature: Timid, Evs: 4hp, 252 S.attack, 252 speed

Flamethrower(STAB)

Energy ball(Covers all weaknesses in one move yeah!)'

HP(Ice)(Covers Resistant Dragons)

Nasty plot(Boost that average 81 S.attack to a Mamoth 162 S.attack)

Note if I get B/W and can Migrate it I will switch energy ball for Solar beam but if you have suggestions please nothing from Gen V

Answer 1

I'd invest the 4 EVs into Defense, myself. It's best to make sure Defenses share the same general base as HP before you invest in the HP stat. Investing in Defense at this point actually means a tiny bit more bulk.

As for the moveset, I'd say this is good. Taking a Defensive approach is good too:

/ 252 Special Defense / 252 Speed / 4 HP /

Will-O-Wisp
Flamethrower / Heat Wave / Fire Blast
Energy Ball / Solarbeam
Roar

Just giving another option, since your offensive set is good too.