The Charger would be wrestled down onto the ground if it failed to kill its target, leaving it vulnerable for a few seconds.
Finishers performed by the companion would have triggered Arcane Ultimatum for the Warframe.
Although this mod has been removed from previous owners inventories and is not present in the codex, it was still possible to acquire via transmutation until Hotfix 21.3.1. Existing copies of the mod aquired this way remained in their owners inventory.
If the Charger was smaller than the target and began to wrestle with the enemy, it might grow in size for the duration of the ability. (Confirmed, especially in extreme cases. Such as wrestling with the Juggernaut Behemoth)