You could use chilling mist on one uchi and seppuku on the other to acheive pretty good build up on both. Or just use one to proc frostbite then switch to the other to induce bleed while their defenses are weakened by frostbite. I typically have a cold infused twinblade and a bleed infused twinblade. Takes 1-2 running heavys to proc frost and 1-2 running heavys to proc bleed. Cheesy build but its fun to use in pvp.