Zilean
In the first half of Season 4, Zilean was truly a frightening force, capable of countering most compositions with high burst damage. The resurrection effect from the ability Time Warp gave your carry a second chance to “clean up” the enemy team. Opponents needed a relatively long time to recharge their energy, allowing your resurrected carry plenty of opportunities to deal damage.
However, as we moved into Season 4.5, carries that deal damage over time began to dominate the meta, significantly reducing Zilean’s value. Dominant champions like Kayle, Olaf, and Tryndamere can deal tremendous damage with basic attacks, without relying on energy recharge to use their abilities. As a result, units revived by Zilean can be taken down very quickly; perhaps this champion can only effectively counter compositions based on Aurelion Sol.
Yone
One of Yone’s most powerful aspects in the first half of Season 4 was that this unit could deal good damage regardless of the items equipped. This is because the additional damage from Yone’s ability was always equal to 100% of the target’s lost health. Combined with the effect of reducing defensive stats, Yone could fit into any composition while still dealing a considerable amount of damage. Therefore, Yone consistently ranked among the strongest 5-cost champions in Teamfight Tactics during the first half of Season 4.
However, as we transitioned to Season 4.5, the damage effect based on lost health percentage was removed from Yone. Additionally, with the introduction of units that can deal direct damage (like Samira) or greatly empower compositions (with items crafted by Ornn), players no longer need Yone to “cheat” power. Thus, even though Riot buffed Yone’s base damage, he currently remains significantly weaker compared to the first half of Season 4.
Sett
While Sett is not a terrible champion, his value at this time has considerably decreased compared to before. Without the effect from the Brawler trait, Sett struggles to withstand the significant damage since opponents can quickly reduce this unit’s health to a dangerously low level. Even if Sett returns to the battlefield in peak condition, it is still challenging for him to single-handedly face the entire enemy team. Therefore, Sett is not a champion that will help you “turn the tide” or overcome difficult matches.
The advice is to avoid risking investment in Sett during the late game. Other options like Ornn, Azir, or Swain are all stronger than Sett in terms of damage output and providing beneficial effects for teammates. You should only purchase Sett if you already have a strong enough composition, as this champion will provide a significant amount of damage to the player.