Unlike modes like ARAM or URF, in All For One mode you should play champions who can stack power or have skills that can affect all 5 members of your team or the enemy team. Such champions are not only powerful but also provide a very interesting experience when playing them.
Here are some champions you should try at least once in All For One mode:
Karma
Karma used to be so strong that she was played in all three lanes: Top, Mid, and Support. This champion can build tanky, AP, or support items in a very diverse manner. In All For One mode, having 5 Karmas means you can freely build items according to your playstyle and still be extremely powerful. When all 5 team up, this is an incredibly hard-to-defeat lineup due to the massive shields from the combination of R+E buffing the entire team. When split-pushing, if you cleverly use R+W and E, you can still survive even when being chased by many enemies.
Wukong
After his rework, Wukong became one of the few champions capable of knocking up 5 enemy team members multiple times, with even his clone able to knock up enemies. Now imagine having 5 Wukongs in the same lineup, continuously diving in and knocking up opponents with both the clone and the original during team fights. Often, enemies will be taken down before they even hit the ground.
Additionally, Wukong’s clone can use some skills like the original, so all 5 players should use the same skin. This will confuse enemies greatly and make it hard to distinguish the real from the fake among your team’s members.
Lee Sin
This champion is almost guaranteed to win in All For One mode, but it cannot be denied that he is extremely fun to play. The reason is that very few people do not know how to play Lee Sin, reducing the chance of anyone being in a testing mode. Moreover, Lee Sin is also a very powerful champion at level 3, having all the elements from shielding allies with W, single-target or multi-target damage with Q+E, and mobility… Finally, there are the 4-5 person Dragon Kicks during team fights, where opponents will be kicked back and forth like a soccer ball, making it very worth trying at least once.
Zac
Similar to Wukong, Zac is one of the champions capable of knocking up 5 enemy team members multiple times. Especially, Zac’s ability to engage from afar is among the fastest and longest in League of Legends, making it very difficult for enemies to anticipate Zac’s extremely surprising Elastic Slingshot jumps.
Although Zac may be slightly disadvantaged in the early game due to being a melee champion, once he has a few tank items, taking down Zac will be extremely difficult. Zac will continuously heal with his passive Cell Division and knock up enemies with his Q+E+R.
Malphite
Malphite is already quite dangerous in regular modes. Now in All For One, enemies will be extremely cautious when standing close together because they could be smashed to pieces before they even touch the ground.
In the laning phase, Malphite can also be very annoying because just throwing out Q and retreating can make enemies lose a significant amount of health. By the time he reaches level 6, sometimes just a slight unexpected movement can force enemies to Flash away. Another advantage of Malphite is that you can build tank, AP, or AD, all of which are quite interesting because Malphite’s skill set significantly enhances power for all three playstyles. Thus, enemies find it very hard to build items to counter your team’s “chunky mountains.”