Edge had decided to bait Karna , by infuriating him and leading him right into a trap where an ambush party would be waiting for him in advance.
Much like what happened in the conquest for Purplehaze city . Edge planned on taking down Karna using sheer numbers. However , what Edge did not know was that he was a little guy when it came to scheming , nowhere near the sophistry of what Rudra had achieved in the field.
Karna had a talk in great length with Rudra , about how if he would be a team captain playing against team japan , what would his gameplan be to win , and naturally Rudra thought long and hard about this question and finally arrived at the conclusion that the best way to win was to dwindle the teams numbers.