Breloom is quite good with spore, seed bomb, mach punch, sword dance. 252 attack speed evs and 6hp evs.
Breloom is a very strong pokemon that can pose threats to many teams with its grass/fighting nature and its diverse moveset. Breloom brings sleep and priority to the table, which is what sets it apart from other physical attackers. It possesses enormous utility in Spore, which is essentially a guaranteed cripple on any opponent that isn't Grass-type. Additionally, Technician, when coupled with an amazing Attack stat, lets Breloom utilize very strong Bullet Seeds and provides it with powerful priority in Mach Punch to deal with faster threats.
Since your Breloom is from an egg (unless you got lucky and got spore), I suggest not using it. I suggest finding a Shroomish into the wild, not evolving it til it gets spore and then using it. I personally use Breloom myself and think it's a great lead in competitive battling.