Keep Learning
Before the 12.1 update, the “Keep Learning” core was one of the hardest upgrades to use in Teamfight Tactics. With the requirement that Scholar champions must survive to gain additional skill damage, you needed a long winning streak to get plenty of attack stats from this technology core. Clearly, to realize that, players had to be extremely lucky, such as getting early team upgrades, assembling many “signature” items; a condition that was too difficult.
However, with the rework in patch 12.1, the “Keep Learning” core will be much easier to use. Basically, Scholar units will definitely receive 2 skill damage from this core; if they survive, they will receive additional stats similar to that. Therefore, your Scholar units will gain a significant amount of damage from this core regardless of whether they survive or not. With Heimerdinger being buffed and Lissandra not being nerfed, this core will be even stronger in the next patch.
Custom Armor
To say the least, this core is designed for players who are “unlucky,” as it provides a substantial amount of defensive stats to units without items. Typically, you won’t equip items on champions when the items are too poor, and that’s when the “Custom Armor” core shines. Moreover, this technology core also serves as a good support option for compositions relying on a single main carry. The fact that all support units without items become “tanky” will help the main carry survive extremely well.
For these reasons, Custom Armor was not a bad core in patch 11.24, and there is a high chance it will become even stronger in the upcoming update. This is due to Riot significantly increasing the additional armor/magic resistance stats of this core in patch 12.1. Another noteworthy point is that the additional stats of Custom Armor also apply to summoned units on the battlefield. Combined with the buff to the Innovator trait, this core promises to become extremely powerful.
Surging Incense
Ironically, even though the Mage trait is very strong, the technology core that directly supports this trait – Surging Incense – is rarely selected. The reason lies in the fact that this core buffs attack speed stats and is only suitable for champions that deal strong physical damage. Meanwhile, in compositions like Jhin – Protector, Mage – Scholar, there are too few champions benefiting from this attack speed stat. As a result, Surging Incense is not favored despite being a powerful core.
In patch 12.1, the attack speed stat of this core has been buffed to 50% and promises to open up new playstyles around it. For instance, a 6-Recycling team combined with Janna and Taric can deal a lot more damage when Ezreal and Trundle have high attack speed. Additionally, the 6-Assassin playstyle combined with Mage is also worth considering with the Surging Incense core.