Beast Out

Beast Out is when MegaMan.EXE absorbs a Cybeast, either Falzar which is a large hawk/phoenix or Gregar a wolf to become Falzar/Gregar Beast MegaMan you can see these forms in the games MegaMan Battle Network 6 Cybeast Falzar/Gregar. Also MegaMan can do cross form (it's similar to Double Soul but longer) with beast out.

In the games, after Beast Out is introduced, it can be triggered by using the Beast Button, located just underneath the "OK" button in the Custom Screen. A counter appears in MegaMan's emotion window - this shows how many turns his Beast Out will last if used. Battling without initiating Beast Out will refill the counter by 1, to a maximum of 3.

During Beast Out, MegaMan gains several abilities, inclusive of a rapid-fire buster, and chips being auto-targetted so short-range chips become more useful. He can also charge non-elemental chips to unleash the Beast Out's special attack. When used with a Cross, this forms a Cross Beast, with the benefits given by the Cross and the Cross Beast having its own unique special attack. Beast Out also can utilize Full Synchro.

Gregar Beast Out
Taking form of the Cybeast Gregar, Megaman gains an extremely fast-firing buster, along with Super Armour, allowing him to execute attacks without the worry of being interrupted by taking a hit. Non-elemental, non-dimming chips gain +30 damage, and the chip charge attack is a double claw slash that hits for 60 damage each, increasing by 10 damage for each increase in Buster attack.

Gregar Beast Out also gains access to the following Cross Beasts:
 * Heat Beast: Chip charge attack becomes Great Fire, that hits a wide area for 80 fire damage, increasing by 30 damage for each increase in Buster rank.
 * Elec Beast: Chip charge attack becomes Big Thunder, that hits a wide area for 70 paralyzing elec damage, increasing by 30 damage for each increase in Buster rank. This attack also cracks the panels it hits.
 * Slash Beast: Chip charge attack becomes Slash-X, hitting in an X formation for 80 sword damage, increasing by 30 damage for each increase in Buster rank. If the locked-on enemy is in line with MegaMan, he will hit it for double damage.
 * Killer Beast: Chip charge attack becomes Killer Tail Arrow, hitting the locked-on enemy for 100 cursor damage, increasing by 30 damage for each increase in Buster rank. This will also cause bugs to the target.
 * Charge Beast: Chip charge attack becomes Charge Bite, which first stuns all enemies before dealing 100 fire damage to the locked-on enemy, increasing by 30 damage for each increase in Buster rank.

Falzar Beast Out
Taking form of the Cybeast Falzar, Megaman gains a fast-firing buster that fires down his entire row along with covering 2 columns of 2 rows beside, along with Air Shoes and Float Shoes, allowing him to move over any panel without harmful side effects. Non-elemental, non-dimming chips gain +30 damage, and the chip charge attack is a double claw slash that hits for 60 damage each, increasing by 10 damage for each increase in Buster attack.

Falzer Beast Out also gains access to the following Cross Beasts:
 * Aqua Beast: Chip charge attack becomes Aqua Spiral, that hits the 2 panels ahead 5 times for 20 aqua damage each, increasing by 10 damage for each increase in Buster rank.
 * Tengu Beast: Chip charge attack becomes Tengu Storm, that hits a T-shape for 50 wind damage, increasing by 20 damage for each increase in Buster rank. This attack hits 3 times at the end column of the T.
 * Tomahawk Beast: Chip charge attack becomes Wing Boomerang, circumventing the perimeter of the battlefield for 2 hits of 70 wood damage each, increasing by 20 damage for each increase in Buster rank.
 * Ground Beast: Chip charge attack becomes Drill Drive, hitting all enemies down the row for 110 breaking damage, increasing by 20 damage for each increase in Buster rank. MegaMan is invincible during this attack's execution.
 * Dust Beast: Chip charge attack becomes Dust Shoot, hitting 6 random panels in front of MegaMan for 100 breaking damage each, increasing by 20 damage for each increase in Buster rank. This attack also cracks the panels it hits.

Beast Over
When a Beast Out or Cross Beast expires due to the emotion counter running out, MegaMan enters a Tired state. In this state he cannot achieve Full Synchro, though he can still use Crosses. He also gets an option to use Beast Over. In this case, MegaMan becomes fully uncontrollable for the following turn, turning invincible and randomly jumping about, firing the buster, and using loaded chips. When the Custom Gauge fills, Beast Over immediately expires, forcing MegaMan into an Exhausted state, where his Buster stats are reduced to 1 each, gets a HP bug, and cannot enter Full Synchro.

Anime
In the anime, MegaMan's Beast Out can only be triggered when he is in a dangerous situation while Trill is around. The Beast Out transformation cannot be controlled, sending MegaMan on a rampage, attacking both friend and foe until the transformation is forcefully canceled. In Beast+, MegaMan can utilize Beast Out through Beast Out chips, and in this state he can control the transformation.