Destroy the Infiltrator and grab plenty of loot after another tricky boss fight.
The bonus requirement for this fight is that you defeat the Infiltrator before the lanterns over the arena light up. In terms of tactics, keep close and to his front. If you give him space, he’ll use a jump attack that you’ll struggle to avoid and pelt you with ranged attacks. Staying at close range means he’ll utilise horizontal combo attacks and follow up with a vertical attack, but there’ll be a couple of beats in between as he switches directions.
Ideally you want to stay close, making him reel off his horizontal combo, which you can avoid, but don’t back off too much as you want him to follow up with the vertical attack, giving you time to nip in afterwards and do some damage. When you whittle his HP down to half, he’ll bring his rear leg into play by trying to stab you with it after the combo if you remain in front of him. It’s fairly easy to avoid. If you hover around his sides instead, he’ll pound his leg into the ground to damage and stun you, and as the range is fairly extensive, you’re better off at the front dodging the easy-to-avoid attacks.
During the next phase of the fight, he’ll tossing larvae at you in sets of 4. Destroy them as soon as possible, as if left to grow, they’ll be able to ensnare you when you walk over them as well as giving HP points back to the Infiltrator. If you’re struggling to purge all of them, you can counteract their HP replenishing effects by popping a Fire Rune into your gauntlet and lighting up the Infiltrator to cause persistent damage. On a final note, avoid the middle of the arena as stepping into this area will drain your MP.
Once you’re victorious, you’ll receive the Crystal of the Traveller, a Big Sealed Rune and Uras Polesword. Initiate a conversation with Yetka and hand over the Ancient Plates to receive a Lightning Resistance Shard, Magic Resistance Shard, Magic Energy Shard and Poison Resistance Shard. Continue up the staircase just behind Yetka to trigger a cutscene.
Ask the Crippled Rhogur about a reward and probe into his obsession with human skulls, which you’ve already started amassing. Head left and into the room beyond to find a lever. Pull it to open up a shortcut to the checkpoint at the foot of the stairs. Don’t head to the checkpoint just yet though. Make your way up the stairs to the sealed portal, that’s now open.
Pop through and collect a Magic Energy Shard, an Energy Shard, an Empty Bottle, 2 Small Sealed Runes and a Codex Greatsword distributed amongst the chests in here. Once you’ve got the loot, pop back through the portal and head back to Kaslo.