Scizor

Great League: 2 / 5

Scizor is the offensive version of Forretress, trading away durability for more offensive options, which include much faster, low energy-demanding moves. This enables Scizor to apply more shield pressure with very frequent charge move usage, though the lack of bulk results in more losses in neutral fights such as against Blastoise. To add more salt to the wound, the tankiness difference between Scizor and Forretress becomes more apparent when Scizor begins to lose certain matchups that Forretress would win, like versus Umbreon and Deoxys Defense Forme. Overall a really cool looking Pokemon that still bugs Grass-types, but maybe leave it to its niche PvE roles. As a side note, due to Scizor's low bulk, it really REALLY hates its only weakness to Fire. For example, Fire Spin Charizard actually melts Scizor before it even gets an opportunity to use Blast Burn. 

Ultra League: 2.5 / 5 

With a higher CP cap in Ultra League, Scizor gets to utilize its offensive potential more. While it deters Psychic and Grass, though, a lack of sufficient durability and relatively low power moves prevent Scizor from obtaining a higher rank. Interestingly enough, even with Night Slash and the Steel typing, Scizor still loses most of the time against either form of Giratina depending on movesets and shields. There are better Steel-types out there.

Master League: 1.5 / 5

Scizor's max CP of 3001 is somewhat inadequate when considering its competition in Master League. Bug and Steel coverage offensively is almost useless in this league, where Dragons and Steel-types are ubiquitous and dominating. Scizor get some points for wins against common Fairy-types, but losses against most of the meta discourages its use.