There are two ways to fix Sceptile.
Method one is what
>>53689312 suggests. Swap its Physical and Special stats, and swap its Hidden Ability for a more useful one (Sharpness IMO is perfect for it)
Even without a bump to its physical movepool, or even without swapping its HA, just swapping the stats would make Sceptile so much better.
Method two would be to expand its Special movepool. If it has a Physical move of a type, but not a Special move of that same type, then give it one.
>Earth Power to match Earthquake>Tail Glow and Pollen Puff to match X-Scissor>Power Gem to match Rock Tomb>Dark Pulse to match Night SlashEtc.
IMO just swapping its stats and HA would be much easier. No massive movepool changes necessary (Though I wouldn't say no to it)
We've seen stat buffs/nerfs and ability changes before between Gens. No reason not to touch one of the most popular starters.
