What approached him was a ridiculously large bear with brown fur and black markings around its neck. Each step it took resonated with the earth, and as it approached him, it gathered mana which was thrice as abundant as the outside, and stomped, making spikes rise, trying to pierce him. He jumped and slashed, hitting the bear, causing superficial wounds which started to mend.
"This bear can manipulate the earth, and it was obviously released just now, or I would have felt it, well, good for me, I get the marrow, heartblood, heart and flesh,, he mused as he jumped on the walls approaching the bear. He then swung his sword, cutting off its arm. "Still not dead, huh? I guess just my sword intent isn't enough, but if I use laws, wouldn't that be cheating?"He then spun back, landing several metres ahead. The bear was no longer roaring recklessly but stood on fours, well threes now, its arm was cut off and observing its opponent, but alas, if only it had done this earlier.
He took out the key and injected his sword intent as he evaded earth attacks from the bear, who had decided not to let him get within 10 metres, as that was the effective range for mana sword attacks. He then jumped 20 metres back and took his hand back, the bear, as if gloating, its opponent had given up, finally saw the movement but didn't pay too much attention, as it knew mana sword attacks were meaningless.
He launched the key, which hit the inattentive bear on the head, penetrating its skull like skewering butter with a sharp knife. The bear fell, its eyes still wide and disbelieving as he approached the corpse. Skewered its chest, took out the heart, and drained the heart blood into an empty jar, loaded it into a space ring, skewered the flesh and put it into the ring.
He then followed the map heading to the centre of the catacombs. Nothing uneventful occurred afterwards as he only met fifth or fourth level magical beasts, slew them, took marrows, heart and heartblood, and headed to the centre. A day later, he finally reached the centre, and saw a large statue, which emanated boundless strength, with a keyhole on its forehead, and made one feel to kneel. But for he who had thirteen laws, he just scoffed and approached the statue to insert the key.