As for skills and balance changes, they are basically nerds. Grinding Gear Games does not deal with uncommon skills, but always states that it does not allow interesting skill interactions. This can be seen even in the middle reaches of the league. A few weeks after entering the league, they weakened a very popular project and did not tell anyone. As someone who likes to spend time instead of meta-building, as more skills get older, my choices become smaller and smaller.
I am very happy to see some of the Vaal skills gains. My protagonist, this alliance, has been using Vaal Land Slam and has achieved great success. At least, the new skill in the ultimatum is really cool. They are all related to blood, such as blood blasting, or a new layer of defense for petrified blood. The harvest looks terrible, and the ability to apply Corrupted Blood to the enemy through the Corruption Heat skill, after death due to Corrupted Blood in the past, feels absolutely demonic.
For me, the main attraction of Path of Exile has always been to find and use weird and POE Currency and skill interactions, and this has not changed. Note that if you don’t fully understand the many mechanics in Path of Exile, the next paragraph will be meaningless.
The protagonist of my alliance uses Facebreakers and therefore has no weapons (unarmed). But the really interesting interaction comes from the new shield introduced by this alliance called Mahuxotl's Machination. This adds six cornerstones to my character. These cornerstones are mixed with energy shields and POE Orbs, and it takes a long time to really explain. The biggest factor is that half of the elemental damage I received has become Chaos damage. I also have a helmet that increases my fire resistance by 75%, but significantly reduces cold resistance and lightning resistance.