Never take a large fleet against the Kultorask. The more ships you bring at it, the faster it heals. You see, it has an ability called Nano Leech that when maxed makes it nigh-immortal because it drains health and antimatter from your ships. Take as few ships as possible against it. It has no abilities that affect titans or starbases, so use that to your advantage. Aside from that, just keep your frigates away from it. More frigates is just more fuel for the fire. At maximum level of Nano Leech, no frigate can put out enough damage to surpass the hull repair rate caused by that frigate. Capitals+titans+starbase-frigates is the only way to do it.
EDIT: bomber spam is also useful because Nano Leech doesn't effect SC. Just make sure to keep your carriers away from the titan though.
