Major Overhaul:
Focus was on reworking Simic and Gruul. Simic's Landmill archetype was quite lacking and required a lot of bad cards to be run. Now overhauled to a more synergistic and complete archetype within the colour pairing of Card Draw/Hand Size. This gave some space to Gruul which mostly lacked a cohesive archetype and gave it some focus in Landfall, which was a space Simic was previously occupying.

Also made small improvements to many other colours, in particular removing a lot of weaker cards in Dimir and giving them an additional direction with the Rogue Mill theme. Also removed a lot of weak cards in Golgari and Selesnya, giving them a bit more power and synergy.

Also added in the check dual lands and the Kamigawa utility lands to give more interest in the land slot. Also moved out some of the weaker/specific colourless cards in favour of more ramp.

Staples also saw a minor improvement, mainly in giving more of a counterspell identity to Blue and giving more interesting cards to Black. Vandalblast was also added to help keep down the strong artifact archetypes and give more artifact desctruction to Red, which it was lacking.

Overall, helped out most colours/guilds to give them more synergy and remove the generally weak cards in favour of stronger, but also more interesting ones.