This guide is my attempt to help you understand the attacks of the 3 elemental bosses before the final stage of your run. This will not include the stage 4 boss or the mini-bosses on each floor before their elemental stage boss. I wan't you to experience the stage 4 boss for yourself, and the mini-bosses are buffed up versions of chaos army fodder.
All bosses have 5-6 attacks and a signature move that appears every 3 stuns. These attacks can be in any order, except for the signature attacks. Any boss will not repat an attack in a combo. That means they won't repeat an certain move until after the stunnable period.
For every stage up you go, the bosses will attack faster, add an extra chain to their combo, have more projectiles (Dependant on attack) and have a smaller period to stun and to do damage while stunned.
When I say extra chain, it means they will use 4 attacks instead of 3, etc. By default, stage 1's elemental boss will use 3 of their basic attacks, then enter a stunnable state. When you get to stage 3, that will be 5 attacks before they stop to rest, which only further states the importance on not bringing sprites, which I say below. Something else to keep in mind is sprites. Sprites are artifacts you can start with or pickup that do different DoT's based on their element. AVOID THESE. Most of these will automatically trigger the boss's stun period by damaging them, leaving you no time to get a combo in or even get close to them for that matter.
When you hit stage 2 & 3, each boss gains a new attack. Freiya turns into a moving ice block, Atlas will Slam the ground around him and send barriers at you, and Zeal makes rings of fire. All of them are a little mixup, but are still managable none-the-less.
Before fighting the boss, you can destroy the red crystal for exactly 75 health worth of orbs regardless of stage. These cannout be retrieved after the fight or during the fight. Make sure you don't waste gold on a health potion when you could have topped mostly off with the crystal.
Final basic: Use different elements per boss. Don't be the guy who didn't save up a water arcana for the stage 3 flame empress. Earth is weak to wind, fire is weak to water, and water is weak to lightning.
Frost Queen Freiya (Breaking the Ice)
These will circle around Freiya before launching towards you in sequence. Simple to dodge, start from top/bottom and move around the edge of the arena.
This attack starts as a large focused beam based on where you are standing. It will split into two and move around Freiya until they have gone slightly behind her. If she is in a corner while she casts this, you will take damage as you will be incapable of getting behind her or dodging the first beam.
Freiya will charge to your location and prepare to swing. Simply dodge away.
Freiya will summon two circle indicators in a corner of the map. These will rain hail and freeze you solid if they hit you. You cannot dodge through the middle. Go around the sides of the indicators. This attack is also a free chance to damage Freiya if you're quick enough, as she stays still until the indicators go away.
On occasion, Freiya will summon these 3 water globes to land near you. One will likely be centered on you. Prepare to dodge away from the two that are not centered on you. If all 3 center on you, dodge at a diagonal angle.
Very similar to the small frost balls, but instead these lances will charge straight for you, and will not collide with each other afterwards. stay the same distance from Freiya, but move around her. That way the lances will miss at pinpoint and not hit you after they arc back out.
On Stage 2 & 3, she will enter an undamagable mass of ice and charge towards you with slower turning. Keep moving and dodging around/towards her to keep her away due to the slow turning
This attack is very similar to the frost balls that she normally tosses out. However, these come out faster and longer. Any arcana that reflect or destroy projectiles is fanastic against this. Otherwise, try to get her in a corner when she's about to use it, and start near her. Follow the edge of the arena and you might get hit by the last few, or you might not get hit at all.
Personally, I found her the easiest of the three bosses. She has easy to read attacks, and a lot of projectiles that can be destroyed or avoided.
Flame Empress Zeal (Feel the Burn)
This chain kick can technically be counted as two attacks, but it really only counts as one. The first is she simply does one kick, arcing fire infront of her in 3 directions, anywhere on the arena. The second is the tricky bit. She'll charge toward you with a trail of fire, then start 3 kicks when right on-top of you. If you see her charge with the trail, stop. Wait for her to get near, and then dodge away horizontal to her. If you dodge too early, she'll kick you mid dash, too late and you're already in the chain.
Zeal will enter a corner of the map and dash across the full diameter of the arena. Small embers show on the ground moments after she teleports to the corner. If you're not stuck in one of her combo's, just take it slow and don't panic dash into these. If you're in one of her combos, you're SOL. When she does this attack, she will stay at the end of her dragon's path. If you send projectiles towards her during this attack, they will still damage her as usual, but will not stun her if she does not end her combo there.
Zeal will stamp the ground sending a viariable amount of shurikens based on the stage. these can be destroyed, but do not track you. Get between or around completely if you cannot destroy any of them.
Just about the same as the shurikens, Zeal's fireballs will beam towards you one by one. start in one side of the arena, follow the wall until she runs out of them.
One last attack I've noticed after stage 1 is she will create a variable number of fire rings with indicators, similar to Freiya's large water globes. These are often easy to dodge.
Zeal's Signature attack will have her jump in the air with a white outline and slam into the center of the arena. Meteorites will then begin to pelt to ground. When you see her jump in the air to start the barrage, get moving and don't stop. When you keep running without stopping or making sharp turns, you will speed up. This speed will help you avoid those meteors far more than dashing, as you don't have to commit to a single direction, making it easier to avoid ones that fall in your way. However, in stage 1 and rarely in stage 2, the meteors will fall slow enough to simply dodge out of the way right before it lands. This does take a bit more effort on the timing, but the results can be the same if done right. A side note, the arcana Crashing Meteor, summons one of these very same meteors to strike an area after a set amount of time. Ironically, since she always lands in the center of the arena, you can set the your meteor to hit her as she lands to use her own.
I found her to be the most difficult stage 3 boss, but managable on 1 & 2. Lots of fun to play against.
Earth Lord Atlas (Party like a Rock Star)
Atlas will slam into the ground and make a drill of the stone, and fly somewhat towards you. He cannot turn mid flight. If you don't dodge, it will hit you a couple times and the vacuum will leave you vulnerable for his next attack.
Atlas makes 3 rocks and sends them at you one by one. The stage number doesn't matter, it will always be three fists. These can be destroyed, but are far more simple to deal with by dodging around the map. If you have arcana like Obsidian Cascade, which can destroy projectiles and damage the boss, use it here. He stands still and the fists come out slow enough to hit him and destroy them at stages 1 & 2. Stage 3 you might want to focus more on hitting the projectiles while still attacking Atlas
Three lines of pillars will show up, the outer edges will hurt you, and the center will always come up where indicated. It is possible if you dash at the correct time to actually escape the confining pillars, though the center line will still track you. He will stamp the ground before doing this move, so stop moving when he does and be prepared to dodge in a zig-zag pattern. No up-up-down, no down-up-up. Always zig-zag away from this attack, or you'll run out of room fast.
Plain and simple, Atlas summons 5 toxic plants to burst somewhere on the arena lasting until the end of his next attack. Don't walk on em'. These follow the same rules as all poison also. Dark purple is used by bosses and chaos army fodder. Light green is any poison you throw out. Don't get them confused.
Atlas will jump into the air and land were you were. I say were because you dodge away from the indicator that appeared below you, right?
At Stage 2 & 3, Atlas can also make his fist collect as a massive rock, and jump towards you to pound the ground near you. Once he jumps, he keeps his path. Let him jump, then dodge.
Atlas can also start summoning rock barriers 5 projectiles in width after stage 1, and will push them towards you, similar to early miniboss summoners. These are rather easy to avoid, but can align you to one of his followup attacks. Watch where you dodge.
These were tricky for me, but they are simple when you get the hang of them. He'll do like Zeal does and jump in the air with a white outline. When you see this happen, get in the top left or top right corner of the map. Let the spikes come towards you, and dash down, then to the middle, around Atlas, and they'll disappear after their alloted time. This method of doing this leaves you undamaged and now face to face with a stunnable Atlas. Also to note is that you can go through the center of these spikes, but at minimum 3 will likely hit you if you attempt this. If you're having issues with them tracking you, focus on clearing the arena of trees during his first combo. It'll leave you space to kite the spikes when he does this attack.
Stages 2 & 3 made him a nightmare for me to start against, so I recommend that if you don't want to spend as much time with him in his decreased size arena, go to the elder man at the top left of the portal to the Chaos Trials. He can arrange the starting boss. If you see this guy or zeal, pick it. Freiya's attacks are too predictable to let her not be a stage 2 or 3 boss.