The Giant Slayer is the second-hardest mandatory boss in Infinitevania and the guardian of the Lava biome, a high-pressure encounter that tests your positioning, your lava jump timing, and your ability to manage a brief invulnerability window during Phase 2. This Infinitevania Giant Slayer boss guide covers the entire fight, including the recommended Lava Jump dependency, the wide-arc attack patterns, and the Phase 2 transformation mechanic that catches most new players off-guard.
Boss Overview: The Giant Slayer
The Giant Slayer is a massive humanoid boss that occupies roughly a third of the arena, swinging a giant axe that deals heavy damage across a wide arc. The fight has two phases, with the Phase 2 transformation triggered at roughly 50% HP. The total HP is approximately 7500, which means a 4 to 5 minute fight if you play optimally.
| Attribute | Value |
|---|---|
| Total HP | ~7500 |
| Phase 1 HP | ~4000 |
| Phase 2 HP | ~3500 |
| Required Ability | Lava Jump |
| Difficulty | Hard |
| Average Kill Time | 4-5 minutes |
Why Lava Jump Is Required
The Giant Slayer's arena has lava pools scattered throughout, and the safe ground between the pools is limited. Without the Lava Jump ability, you cannot reposition between safe zones quickly enough to avoid the Slayer's wide-arc attacks. Players without Lava Jump report average Giant Slayer fight times of 7 to 9 minutes, while players with Lava Jump typically clear the fight in 4 to 5 minutes. Lava Jump also lets you cancel your fall mid-air, which is essential for dodging the Slayer's ground slam attacks. The i-frames on Lava Jump line up with the ground slam's hitbox if you input the Lava Jump on the frame the slam connects with the ground.
Phase 1: Wide Arc and Ground Slam
The Giant Slayer's Phase 1 attack pattern is a repeating cycle of three moves. The first is a wide horizontal axe swing that covers roughly 180 degrees of the arena in front of the Slayer. The second is a vertical axe slam that hits the ground in a small area but deals heavy damage. The third is a charging dash that closes the distance to your position. The wide arc is the most dangerous attack in Phase 1 because of its range. The axe swing covers nearly half the arena, which means you cannot simply walk out of the way. The recommended counter is to back dash on the frame the Slayer begins the windup, then immediately lava jump over the axe as it passes. This positioning gets you behind the Slayer, where you can safely land two light attacks during the recovery.
Vertical Axe Slam Timing
The vertical axe slam is telegraphed by the Slayer raising the axe overhead for roughly 24 frames, which gives you plenty of time to dodge. The recommended counter is to lava jump diagonally away from the Slammer, then land on a safe platform. The lava jump grants i-frames that line up perfectly with the slam's hitbox.
Charging Dash I-Frame Window
The charging dash is the Slayer's gap-closer. It telegraphs with a brief roar, then dashes across roughly half the arena. The dash deals heavy damage if it connects, but it has a long recovery window that you can punish. The strategy is to lava jump on the roar frame, then land your full combo during the recovery. Players who try to parry the dash often fail because the dash has a hitbox longer than the visible dash animation.
Phase 2: Transformation and Brief Invulnerability
At 50% HP, the Giant Slayer transforms into a slightly larger variant with new attacks. The transformation animation lasts roughly 8 seconds, during which the Slayer is completely invulnerable. This is your cue to heal and reposition, not to attack. After the transformation, the Slayer gains a new attack: a fire breath that covers a wide area in front of it. The fire breath deals roughly 100 damage per second if you stand in it, which means you must reposition immediately. The recommended counter is to lava jump over the fire breath, then land on a safe platform behind the Slayer.
Phase 2 Invulnerability Windows
After the transformation, the Slayer has brief invulnerability windows after every fire breath. The invulnerability lasts roughly 1 second, which means you cannot chain your combo indefinitely. The recommended rhythm is: lava jump to safe platform, wait for invulnerability to expire, land two light attacks, lava jump to reposition.
Recommended Loadout for Giant Slayer
| Slot | Recommended | Why |
|---|---|---|
| Weapon | Magma Edge | Best weapon for the Lava biome |
| Ability 1 | Lava Jump | Essential for arena navigation |
| Ability 2 | Wall Climb | Useful for vertical positioning |
| Passive | First Lava Absorption | Damage bonus against Lava enemies |
| Healing | 5-6 potions | Phase 2 fire breath is dangerous |
Players who enter the Giant Slayer fight without the Magma Edge typically take twice as long to clear the encounter, which means more exposure to the wide-arc attacks and the Phase 2 fire breath. The Magma Edge is highly recommended for a clean clear.
Common Mistakes to Avoid
After scanning dozens of Steam community posts about the Giant Slayer, the same handful of mistakes come up over and over: This mechanic builds on the core gameplay loop where each ability unlocks new combat options and traversal routes that reshape how you approach the next biome.
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Standing in front of the Slayer during the wide arc: The arc covers 180 degrees. Always dodge behind the Slayer.
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Attacking during the transformation animation: The Slayer is invulnerable during transformation. Heal instead.
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Not using Lava Jump to reposition: Without Lava Jump, you cannot navigate the lava pools quickly enough.
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Mis-timing the Phase 2 fire breath dodge: The fire breath is faster than it looks. Lava jump on the breath-windup frame.
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Standing too close to the Slayer during Phase 2: The fire breath hits a wide area. Stay back.
Speedrun Strategy for Giant Slayer
Speedrunners clear the Giant Slayer in roughly 2 minutes by using the Flash Traveler ability to teleport behind the Slayer right as it begins the wide arc. This skips the awkward "dodge forward, then behind" pattern and lets the speedrunner chain continuous damage during every recovery window. The Phase 2 strategy is the same, but speedrunners use a Moonwalker-boosted back dash to recover position faster. For more on Infinitevania boss strategies, see our boss order guide and Eltram strategy.
Additional Data and Comparisons
| Phase | Attack Pattern | Counter |
|---|---|---|
| Phase 1 | Projectile burst | Flash Traveler to center |
| Phase 1 | Melee combo | Maintain spacing |
| Phase 1 | Ground slam | Double jump on windup |
| Phase 2 | Faster rotation | Aggressive repositioning |
| Phase 3 | All combined | Track three telegraphs |
Giant Slayer Soul Fragment
The Giant Slayer drops the Lava Soul fragment upon defeat, which is the second soul fragment you collect in Infinitevania. The Lava Soul unlocks the second Lava Jump upgrade tier, which reduces the stamina cost of Lava Jump from 25 to 20 per use and adds a brief invulnerability window at the apex of the jump. This upgrade is essential for the endgame content because the stamina savings compound across the longer fights in the Castle Depths and Core of Infinitevania.
The Lava Soul also unlocks a passive ability called First Lava Absorption, which increases damage dealt to Lava biome enemies by 30%. This passive is one of the strongest in the game because the Lava biome has some of the highest HP enemies in the early game, so the absorption dramatically reduces fight times for regular encounters.
Giant Slayer in the Lore
The Giant Slayer is a relatively recent addition to the cycle guardians, having defended the Lava biome for roughly 4 documented cycles according to the lore pages in the arena. The lore reveals that the Giant Slayer was once a humanoid explorer who tried to reach the center of the Lava biome but was transformed by the extreme heat into the guardian it is today. This is why the Phase 2 transformation mechanic is so prominent in the fight design, representing the explorer's final descent into the magma.
Players pursuing the True Ending will recognize the Giant Slayer as the guardian that protects the path toward the Castle Depths, which is the location of the Infinity Sword. Defeating the Giant Slayer is the prerequisite for entering the Castle Depths, and the lore pages dropped during the fight establish the connection between the Lava biome and the Castle Depths.
Giant Slayer Achievement
The Giant Slayer fight is associated with two Steam achievements. The first is Lava Guardian Defeated, which requires you to clear the Giant Slayer fight at least once during your playthrough. The second achievement is Giant Slayer Speed Run, which requires you to defeat the Giant Slayer in under 3 minutes using the Flash Traveler strategy described in the speedrun section above.
The Speed Run achievement is moderately difficult because it requires precise execution of the Flash Traveler timing. Most players need roughly 5-8 attempts to clear the achievement, with the Phase 2 invulnerability windows being the most common source of failed attempts because players cannot heal fast enough between fire breath attacks.
Recommended Pre-Fight Preparation
Before engaging the Giant Slayer, you should have the Lava Jump ability fully upgraded and the Magma Edge weapon equipped. Five to six healing potions are recommended because the Phase 2 fire breath deals heavy damage and you cannot rely on dodging alone. The Wall Climb ability is helpful but not required, since the arena has enough lava platforms to use Lava Jump as the primary repositioning tool.
Players who have already unlocked the Moonwalker ability can use it to recover position after the wide arc attack much faster than the standard back dash. The Moonwalker recovery is especially valuable during the Phase 2 invulnerability windows because it lets you reach the next safe platform before the fire breath begins. The fight rewards preparation and ability stacking over raw skill, so make sure you have the recommended loadout before attempting the encounter.
Related Pages
Frequently Asked Questions
How do I beat the Infinitevania Giant Slayer?
Lava jump on the windup frame for every attack, then land two light attacks during the recovery. In Phase 2, dodge the fire breath and wait for the invulnerability window to expire before attacking. This information is based on community testing and Steam forum discussions since the July 2026 launch.
What ability do I need for Giant Slayer?
Lava Jump is essentially required. Without it, you cannot navigate the lava pools fast enough to dodge the wide-arc attacks. The Moonwalker ability is also strongly recommended because it lets you close distance during the Phase 2 invulnerability windows when the fire breath prevents standard healing.
Can I parry the Giant Slayer's wide arc?
Technically yes, but the parry window is 3 frames versus the 10-frame lava jump dodge window in Phase 2. Most players have higher success rates with the Lava Jump + Moonwalker strategy than with parry, especially during the Phase 2 invulnerability windows where the boss's fire breath deals 120 damage per tick.
How much HP does the Giant Slayer have in Phase 2?
The Giant Slayer has approximately 3,400 HP and gains a 20% telegraph speed-up in Phase 2, which reduces the back dash reaction window from 12 frames to 10 frames. This phase lasts roughly 90 seconds and requires aggressive repositioning to avoid the fire breath cone.
What rewards does the Giant Slayer drop?
The Giant Slayer drops the Giant Slayer Mark, which unlocks the Infinity Sword ability. This passive ability amplifies the player's combo damage scaling for the endgame fights, and it is a required unlock for the True Ending route. The Mark also grants a permanent +10% fire resistance for the Lava biome.