Knock-up combo and area burst
Sion brings several forms of setup: ultimate can knock a target up, Q can create a knock-up in a corridor, and his body often forces enemies to group or retreat into a specific area. Yasuo and Orianna punish that type of moment extremely well. Yasuo directly converts airborne control, while Orianna can use Sion as an entry point to place a decisive area effect. This synergy works because Sion does not need to kill alone; he mainly needs to ensure the enemy cannot ignore the first impact.
How to play it. Sion should announce his timing through position, not necessarily through an instant engage. He walks forward, forces enemy movement, then uses ultimate or Q when Yasuo or Orianna are close enough to convert immediately.
Objective-area control
Sion is very strong when enemies must enter limited space: river, jungle, Baron entrance, or dragon entrance. His charged Q threatens the area, his ultimate cuts a path, and his W lets him absorb the first response. Miss Fortune benefits from slowed or grouped targets, while Sejuani adds another layer of control and makes entry even harder. This composition is not only looking to engage; it forces the opponent to choose between walking into control or giving up the objective.
How to play it. You need to arrive before the enemy. Sion prepares the wave or entrance, Sejuani and Sion lock access points, then Miss Fortune punishes targets forced to move through a predictable area.
Durable frontline and extended sustain
Soraka does not turn Sion into an assassin, but she reinforces what he already wants to do: stay present longer than the enemy wants. When Sion absorbs the first rotation with W, Grasp, his health, and possibly Gargoyle, allied sustain can extend the window where he blocks access to carries. This synergy becomes especially interesting in extended fights, when the enemy lacks enough burst or backline access to ignore Sion and reach fragile targets directly.
How to play it. Sion must avoid suicidal engages. With Soraka, it is often better to advance gradually, absorb damage, step back just enough to be healed, then retake space with Q or E.