Riven
In theory, Riven is an almost perfect champion with high attack speed from the Legion system, strong healing from the Divine tribe, and skills that provide a lot of attack damage. Essentially, Riven is designed to be a strong carry champion in the mid-game for a Legion lineup. However, in reality, this champion isn’t as powerful as people think, and Riven is gradually becoming the worst 3-cost unit in Teamfight Tactics.
If you notice, when using skills, Riven does not gain energy when dealing damage or receiving damage from opponents while the ability is active. Therefore, the actual damage this champion deals is not stable at all; just by having strong crowd control units, you can severely limit the damage coming from Riven. Unless there are significant changes to the meta in upcoming patches, Riven will likely still only play the role of “filling the team composition”.
Taric
It’s no exaggeration to say that Taric has one of the best defensive systems and skills currently available. The unique feature of Taric is that his ability not only heals but also provides a massive amount of armor/magic resistance for the team. However, in reality, Taric rarely gets to unleash his powerful ability because this unit is often taken down far too quickly. If you don’t position wisely, Taric can easily become “useless” even though he is a 4-cost unit.
The reason for Taric’s difficulty in play is that this champion has a maximum energy of 200, so the time for Taric to fully charge his energy is incredibly long. In cases where the opponent has a Silence Cloak, it is nearly impossible for Taric to use his skill unless the Mystic effect is activated. To play Taric effectively, you should observe your opponents carefully, positioning this champion in safe spots and avoiding counterplay from items like the Rapid Firecannon or Silence Cloak.
Viego
In theory, Viego’s skill has a high burst potential in the late game as it provides crowd control effects and allows him to possess enemy champions. If you can take the enemy’s carry with Viego, victory will be assured. Despite being so powerful, Viego rarely successfully uses his ability because widespread crowd control units are very dominant in the current meta. For example, Rell can easily counter Viego’s skill.
Moreover, as a 5-cost champion, leveling Viego to 2 stars is extremely challenging. Therefore, this champion is easily taken down when trying to approach the opponent’s carries. The advice is to equip Viego with Guardian Angel and Quicksilver to ensure that this champion can control the enemy team’s carry. You should not build items that increase physical damage for Viego as he does not auto-attack enough to utilize the power of these items.