Blue Buff
After the mid-season update, Blue Buff became an extremely niche item and was almost exclusively used when playing Teemo or Riven. However, with the arrival of the Sorcerer – Star Guardian meta in Teamfight Tactics patch 10.14, Blue Buff suddenly became one of the most contested items due to its overpowering synergy with Syndra’s massive damage.

Even after Syndra was nerfed to 50 mana, the importance of Blue Buff increased significantly, allowing her to cast spells more frequently, resulting in a greater energy buff for the entire team. Essentially, Blue Buff is an essential item for playing the Sorcerer – Star Guardian composition, and you must have this item if you want to secure a top 1 finish.
Giant’s Belt
This item was nearly forgotten in the previous patch as other attack items like Blade of the Ruined King and Infinity Edge were too hot to ignore, making it hard to sacrifice B.F. Sword and Wooden Bow to create this item. However, with the release of patch 10.14 and the overwhelming popularity of Warmog’s Armor, Giant’s Belt is now almost the only item that counters high-health units effectively.

Furthermore, the return of the Super Technology trait with high health units is another reason why Giant’s Belt is becoming increasingly popular. With the effect that deals an additional 80% damage converted to true damage against units over 1750 health, Giant’s Belt is the best item to help your carries take down current meta tanky champions like Jarvan IV.
Thornmail
With so many champions dealing damage like Zed, Riven, and Vayne added to the champion pool, defensive items have become extremely necessary for your tanks to survive. With Infinity Edge being prevalent in every team composition, Thornmail has become incredibly strong to mitigate damage from opponents.

Moreover, the critical damage reduction effect of Thornmail also applies to skills, making this item solidly positioned in the current Sorcerer meta. Perhaps no item right now boasts as strong a defensive trait as Thornmail, so you should consider taking care of your tanks lest they get obliterated and fail to protect your carries.