This guide is for the possible solutions for completing the trials in the game. Some are straight forward, some are not. I used the methods myself for completing the trials and I can confirm they work. If you have a method that you found easier, feel free to share and I'll update.
A side note: Trials can be completed on any difficulty.
Thanks to II OE II, for some information has been taken from his guide and compiled into here.
Also thanks to Cra, CyberEvil, Echilion, EliteShadowMan, Miles Prower CC, Moldredd, Nostendorp, Quid Squid, and Weasel13.
Special thanks to xF02 for the videos.
- Finish the level, defeating the Great Warg with at least one surviving villager
Kill the werewolves as they appear so the villages do not take damage. If you can't get to one in time, throw a dagger. When fighting the Warg, roll away from the villages so he will not lunge at them.
- Finish the level without being healed by any means
Do not use any healing magic or healing fountains. Picking up the life gem also counts as healing, so you can't pick it up either.
The Dead Bog
- Finish the level after killing at least 50 Goblins
There's an infinite spawn where you must blast down the tree. Do not knock the tree down and kill until you've killed 50.
- Finish the level after beating Pan's trial in 5 movements
Clockwise movement: outer, inner, outer, middle, inner
- Finish the level and defeat the Ice Titan in less than 1:30 minutes
As soon as you get close to the Ice Titan, use your dark crystal to weaken him. All weak points will be destroyed in 1 hit after this. While climbing and shimmying over, press A to hop up or across to speed up your movement but remember to hold RT to keep from falling off. If you get knocked off, press start and World Select the stage again because it may autosave and you will not have your dark crystal again. You will not have much time to finish him off, as you'll only have less than 10 seconds to spare even if you do this perfectly.
- Finish the level after killing 30 Goblins with their own grenades
While you're in the ruins, when you have to use the goblins bombs to blow up a door, simply press RT to grab a goblin and press Up on the Left Thumb Stick + X instead of pressing A. He will light the bomb on their body and they will run and blow up. Repeat this 30 times.
- Finish the level after killing at least 10 enemies while poisoned by Spider venom
On the 2nd spider fight, with the Lycans, you can either hold steady and hold block and wait for the spider to lunge at you, or continue to run in front of the spider and hope he poisons you. Once he does, throw daggers at the Lycans or kill them with your whip. At this point, do not kill the spider. If you're too low on life, use Light magic to regain life but don't kill the spider. Once you're ready, run through one of the caves to trigger an autosave. Restart from last checkpoint, go back and the Lycans will have respawned and you will have your previous kills. Repeat this until you're done.
- Finish the level after killing at least 5 Warthogs
At the very beginning of the stage, as long as you do not break down the door Warthogs will spawn infinitely. Kill 4 Warthogs. You can break down the door with your 5th Warthog and finish the trial upon strangling it.
Waterfalls of Agharta
- Finish the level after killing at least 20 Small Trolls while you are mounted on a big one
When you mount the Big Troll, as long as you do not destroy the rock, Small Trolls will spawn infinitely. Kill 20.
- Finish the level without using Shadow Magic energy
Pretty straight forward. Simply do not press RB throughout the entire level. Dark Gauntlet and Light Magic is fine.
- Finish the level without using a grip attack against a single Gremlin
Do not press RT to grab a Gremlin at all during the level. Either throw daggers or jump and kill with Y combos. Y A A is also a good starter to fighting Gremlins.
- Finish the level after absorbing 20 Neutral Elemental Orbs simultaneously
While fighting the Cave Troll, raise your focus meter and hit him until see you a mass of neutral elemental orbs floating around. This is especially effective if your focus meter is full and you stun him to ride him. Instead of riding him, kill him and you'll get orbs for hitting him and defeating him. If you get hit, your focus meter resets to 0 and you'll have to start over.
Sanctuary of Titans
- Finish the level and defeat the Stone Idol Titan in less than 2 minutes
When you see the titan, use your Dark Crystal to weaken it, this will cause weak spots to only take 1 hit to destroy. Timer starts when you throw the first rock back at her and after the cut scene. Use A to quickly jump up, left, right, or down to make climbing her faster. After weak spot 1, climb strait down to avoid her hand. After weak spot 2, climb straight down to avoid. Now she'll punch the ground and knock you off, that's natural so don't fret. After weak spot 3, climb straight up up to avoid. Grapple to the rock then her face, climb her face and hit her weak spot. The timer may say about 5 seconds, but it gave it to me even because of the cut scene. Don't miss the mini game or you'll have to try again and put your trial in jeopardy.
The Black Knight
- Finish the level and defeat the Black Knight Golem without using Light Magic energy
Do not press LB during the entire fight. If you find yourself taking too much damage, holy water and dark magic daggers do pretty good damage to burn him down. When he summons the puddles of sludge to bind you in place, hold X for the whip combo to hit the puddles before they reach you to destroy them.
The Three Towers
- Finish the level after killing 15 enemies while they are dazed by Fairies
When you start the stage, use all of (or as many as you're comfortable with) your fairies to daze the Lycans at the beginning until you're out then continue as normal. Right before you obtain the Fairy Bottle, you can get around 13 dazed kills from the Lycans to finish it up.
If you start the level without any fairies, you can get fairies within the stage and the fairy spawn points regenerate.
The Dark Lord of the Lycans
- Finish the level and defeat the Dark Lord without using Light Magic energy
Do not press LB during the entire level. To kill him as fast as possible, daggers are your best bet. In stage 1, normal daggers do 120 damage and dark magic daggers do 150 damage. In stage 2, dark magic daggers do 225 damage.
- Finish the level and defeat the Ogre without being hit by his attacks
This counts his arm sticking out of the wall. When his arm comes out, stand as far away as you can. When he's trying to grab you, hit him. When he pulls back, step up and hit him about 3 times then pull away max distance again. Then when you face him completely, stay as far away from him as you can and always move either left or right, never stop. When he's going to smack, just jump once as he hits the ground, turn on dark magic and hit him 3 times, turn off dark magic and continue moving. When 1/2 of his life is gone, he'll hit the ground with his fist. To avoid this, start dashing either left or right when he screams. When he starts to hit, double jump and press X or Y in the air a few times to prolong your airtime so you will not land in the shock wave. Go to the back of his fist quickly and poke his eye out. Now it's more of the same, except he'll add the rock to it. If he is holding a rock, do more of the running and jumping and just double jump to avoid the shock wave. You can turn on dark magic and hit his hand mid air to knock the rock out of his hand. If you're running low on magic, get near the magic fountain and when the rock (only when he's using the rock) hits the ground, refill magic instead of attacking. If he rubs his eye, then this will give you time to overfill your magic meter. Continue this pattern until you poke his other eye out. When he's sniffing for you, just stand still. Once he roars, begin to sprint either left or right and double jump to avoid his hits, do not stop moving. When his head lights up, finish it. If you get hit at any time, press start and Restart from Last Checkpoint and you will pick up after the last autosave (before hand, before body, after 1 eye, after both eyes) so if you mess up, don't sweat it.
The Crow Witch
- Finish the level and defeat the Crow Witch without killing more than 2 of her sons
My method was a little sporatic. When she started spitting eggs, I began jamming down on RT rapidly while rotating LS counter-clockwise. Even during the cut scenes to show she's being hit by the egg, I continued to do it. You can grab eggs that have already landed but you don't have time. I threw 2 of the 3 on the first wave, and had to kill 1 of her sons. On the second wave, she spit out two and I threw both. Remember to beat on her while she's on the ground after the flying mini game.