Not a lot of tactics required here- enemies will keep mobbing you, and you'll keep killing them. Getting the hit counter to 30 isn't so hard- there are no special enemies or ranged attackers here. Just keep a steady, easy flow going, and always counter incoming attacks. Counter when the marker is blue to build up the 10 perfect counters needed for the other optional goal here.
Focus on getting the 30 hit count first- perfect counters are easier to get individually, and less damaging to the orcs, in case you need to rope-a-dope a few stragglers when your kill count gets high. Once you've killed 30, the task ends.
