I bred a Roselia...

[laggless01 51]

I bred an amazing Roselia in my latest run. It momentarily has Extrasensory, Toxic Spikes, Giga Drain and Magical Leaf (perhaps for Technician?). It is Timid natured, and has 31/30/31/30/31/30 IV, which gives it access to HP Fire. It also sports Natural Cure.
I cared a lot for it giving it a 252 SpA, 4 SpD and 252 Spd EVs, trying to make it an offensive powerhouse when evolved.

Since I just beat Serra, the best moves are yet to come, iirc. Any suggestions on moveset?

[Skullgasher 0]

You have a pretty solid moveset atm. I'd recommend replacing magical leaf with sludge bomb once you get your hands on it

[Simon 38]

First off, nice job mate.

Since you're going for a more offensive Roserade, definitely go with Technician, especially since you have HP Fire. For its moveset, I guess Magical Leaf, Extrasensory, and Spikes/T. Spikes/Toxic. Unfortunately, you don't have access to Sludge Bomb on it, which is arguably Roserade's most vital move, but you can either wait to get the TM for it in-game or try your hand at breeding another amazing Roselia where you'll just replace one of the hazard moves for Sludge Bomb. If you wanna know how to do it, just check Etesian's Breeding Guide / Recommendable Sets

[ShadowStar 34]

My favorite Roserade Move-set for Reborn is:

- Grassy Terrain / Spikes / Toxic Spikes / Extrasensory

- Leaf Storm / Giga Drain

- Sludge Bomb

- HP Fire

[Sheep 27]

Make sure you don't drop Giga Drain. For now technician magical leaf is probably better but once you get sludge bomb it's the same power, and therefore giga drain becomes more useful. Shadow ball is a useful coverage move for the future too.

[hallowilicious 0]

just a bit curious, how many egg did you have to throw away? how many time did you have to chain breed?

[laggless01 51]

just a bit curious, how many egg did you have to throw away? how many time did you have to chain breed?

Well...first I had to combine some mons to get a Field mon with the right IVs. (I call that my ent, I can breed via dual-group mons from there on) Then I bred Nuzleafs/Seedots with the right IVs, then Roselias.

After that, I gave a Rose Incense to Roselia and a Power Item to Nuzleaf. Why? Because I have a version of 14.1.1 that had a Breeding bug, so I transferred all the IVs. (It would have taken ages otherwise) Then I got lucky with my first egg out of that pair.

[laggless01 51]

EDIT (double post because of added info after long time):

I swapped Magical Leaf with HP Fire (still unsure about that decision), which makes Extrasensory/Giga Drain/HP Fire/Toxic Spikes. I'm inclined to change the Rose's ability to Technician.
If Sludge Bomb becomes available, which move should I ditch (I know it ain't yet, but perhaps ep.16/17?)? Should I make some adjustments before I evolve it (or level it up to a certain level before doing so? I don't know if the Move Tutor would classify seen moves pre-evolution as relearnable, so...)?

[Simon 38]

Ditch Toxic Spikes for Sludge Bomb to become a Offensive Powerhouse once it is available. Other than that, you don't necessarily need to make any adjustments.

And no, the Move Tutor doesn't work like that unfortunately. It only allows you relearn moves from its current evolutionary state.