Metal Slug Attack Wiki
Ultimate Mission

MSA Ultimate Mission.png

Ultimate Mission is a game mode in Metal Slug Attack.




In order to play Ultimate Mission, the player must be level 25 or higher. No sorties are required to play Ultimate Mission.

There are two daily tries per reset. A stage can be tackled by the player, in which they are limited to units of one faction (like Another Story), with reset times at 00:00 and 12:00 JST - rotating between Independent, Regular, Rebel, Ptolemaic and Aliens respectively. The player has 5 minutes to defeat the enemy.

Each faction's Ultimate Boss selects one of three potential decks as listed below. The first deck mostly contains units affected by Attack and Health strengthening items; this is also the default first-time deck when attempting the stage. After clearing that faction's stage for the first time, the other two decks will also be shuffled in. The second deck is a mix of Rare and Super Rare units, while the last deck consists of the faction's strongest units at the time of the stage's release. Although the pre-briefing screen shows the support used by the AI, the AI is capable of using both Reload and Recovery; Metal Slug Attack support is only used if it is the listed support.

As with all other PvE modes, the AI controls the deck. Usually they will send the units out from left to right. Ultimate Bosses are deployed at random. Regular and Rebel bosses usually appear very late into the match, but Ptolemaic, Alien and Independent bosses can be deployed as early as 80 seconds into the match.

All enemies encountered in Ultimate Missions have maximum status strengthening items applied onto them. These units are all of platinum frame, so they have level 10 status resists and item applications (if applicable).

Time and parts:

  • S Rank - 3 parts, within 2:00
  • A Rank - 2 parts, within 2:01-2:30
  • B Rank or lower (including draw) - 1 part, after 2:30

After clearing (or failing) the stage, the deck composition will change. It is possible for neither the deck or support to change however. If a deck composition needs to be changed, consider using AP Max with a powerful unit to instantly clear the stage.

A raid is considered to be a D Rank, which will only yield one part unless pants are used, in which it's considered to be a S Rank clear. Raiding the stage will not change the deck composition.

Ultimate Boss

The Ultimate Boss requires only 10 parts to unlock, like a handful of Super Rare units such as the Rootmars Slug - however, it is extremely unfeasible to use on such a frame, due to its immense AP cost. Like the Rootmars Slug, further evolution frames significantly cuts down the AP cost. A final AP reduction cost can be obtained with excess parts once it reaches platinum frame; each level requires 15 unit parts, and adds a 0.5% AP reduction bonus from its platinum frame cost, essentially halving it once fully maxed.

As befitting their name, Ultimate Bosses are intended to be used by the faction that it belongs to, as a late-game ending unit with their massive health and damage.

Ultimate Bosses have a built-in frontline production ability, buffs their faction's health and attack (with MSA BuffSkill small +.png 2 and 3 respectively), and treat stun attacks as normal ones. With the exception of the Avatar of Evil, Ultimate Bosses possess counterattacks when staggered.

Ultimate Bosses possess Special Items in order to equip and unlock their skill 2 and higher tabs. One of these items can be purchased from the Mars Shop, while the remaining are acquired from Extra Ops; refer here for the items each Extra Ops provides. Occasionally sales may appear for skill 4 and 5 items, paid with real money, starting from 6.9.0.

Ultimate Bosses cost an immense amount of MSP in order to be put to their full potential. The MSP shop provides large amounts of MSP for this purpose, albeit at the cost of significant medals.

Ultimate Skill

When MSA UltimateSkill small +.png 1 is unlocked, it accesses the Ultimate Boss' ability, while MSA UltimateSkill small +.png 4 is an extension of that ability to further strengthen it. The final equip set of items in each Ultimate Boss takes considerable investment, but makes the Ultimate Boss incredibly powerful.

With the exception of Super Metal Slug Attack and Repair, all Ultimate Skills are a less-refined version of the Relief Supplies, whereas the UM version only lasts half of the original duration of their respective Power-Ups.

In order to use the skill, the Ultimate Boss has to be placed in the deck alongside units belonging to its faction. Depending on the Ultimate Boss, the start-up time for the ability varies from instant to a few seconds of in-game time. The skill only activates for the first Ultimate Boss deployed and can only be activated once.

  • Super Metal Slug Attack (Golden Slug Phoenix): The Golden Slug Phoenix emits a shockwave with infinite range and full pierce, damaging units by a percentage of their maximum health like the Metal Slug Attack support with a maximum of 100% of their max HP. It can also damage the base, but is capped at 25,000 damage. As with the normal Metal Slug Attack support, it does not damage enemy units in a state of invulnerability.
  • Attack Fever (Perfect Jupiter King): Causes the units' special attack to be used indefinitely temporarily, lasting up to 30 seconds.
  • Jamming (Avatar of Evil): Completely jams the enemy, disabling almost all of their capabilities, filling up their special attack load bar, halting the enemy's AP production, support load time and halts production lock timers, lasting up to 12 seconds.
  • Fever Time (Invader King): A variant of Fever Time that instantly resets deployed units production time, allowing to deploy them instantly, provided that they have sufficient AP to do so. Removes any production lock effects on units as long as the ability is active, lasting up to 30 seconds.
  • Repair (Celestial Ruler Rokker): Instantly repairs the player's base, restoring all health and "overcharging" it (causing a yellow overlay on the base health bar), up to 10 times its normal health.

List of Ultimate Bosses

Ultimate Bosses
Unit Update Faction Ultimate Skill
 Golden Slug Phoenix 5.0.0 MSD faction Regular Army 24px.png Regular Army MSA UltimateSkill small +.png Super Metal Slug Attack
 Perfect Jupiter King 5.0.0 MSD faction Rebel Army 24px.png Rebel Army MSA UltimateSkill small +.png Attack Fever
 Avatar of Evil 5.2.0 MSD faction Ptolemaic Army 24px.png Ptolemaic Army MSA UltimateSkill small +.png Jamming
 Invader King 5.4.0 MSD faction Aliens 24px.png Aliens MSA UltimateSkill small +.png Fever Time
 Celestial Ruler Rokker 5.8.0 MSD faction Independent 24px.png Independent MSA UltimateSkill small +.png Repair


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Game Modes Another Story | Attack!List of Standard MissionsList of Elite Missions | Battle and Team Battle | Combat School | Extra Ops / Guild OpsList of Extra Ops | Online | P.O.W. Rescue | Rank Match | Special Ops | Ultimate Mission | Battle Tactics
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Extras Patch Notes | Music | Update History | Event Schedule