Nova Strike

Nova Strike (ノヴァ・ストライク) is the Giga Attack of the Fourth Armor and the Ultimate Armor in the Mega Man X series. X first surrounds his body with immense energy, then performs an invincible flying tackle that plows through (and destroys) enemies almost effortlessly. Aside from its offensive capability, the Nova Strike also permits quick mobility throughout most levels.

Mega Man X appearances
In Mega Man X4-Mega Man X6, X can use this attack infinitely (except in the Fourth Armor's version, where energy needs to be refilled like normal Giga Attacks). In Mega Man X8, the Nova Strike is modified along with the Ultimate Armor. It now has Weapon Energy (WE); however, it recharges over a small period of time (a matter of seconds, in fact). The only downside to this is that it prevents the Nova Strike from being used over and over. To compensate for this added weakness, the Nova Strike's travelling distance is increased, and it can now destroy all bosses in only two hits (the first hit depletes all of the boss's energy but one unit (four units in Hard mode) triggering the boss's overdrive, which is always mandatory).

In Mega Man X4-X6, the Nova Strike counts as an air dash and therefore X cannot activate the Nova Strike and air dash (or vice-versa). He also cannot dash on the ground and activate it. Although the Nova Strike is an invincible attack, it doesn't protect X from spikes; but in Mega Man X5, X could use it to travel through the lethal laser beams in Zero Space without damage (or death).

Just like how the Ultimate Armor in Mega Man X: Command Mission is given a complete overhaul, its Nova Strike is also different: now X fires a series of explosions.

Other appearances

 * In the Mega Man Zero series, one of the attacks from Copy X's first form is the Nova Strike.
 * In Project X Zone, X uses the Nova Strike in his Up+A attack without an armor and in his special attack with the Ultimate Armor, the later launching the target far away with its power.
 * In the sequel Project X Zone 2, the normal version of Nova Strike is now used in his assist attack, and its special version was modified. After equipping the Ultimate Armor, X uses Nova Strike on the opponent, launching the target up. With Nova Strike still active, X flies to the enemy's direction and pushes him, rotating the enemy to crush him on the ground.
 * X uses the Nova Strike in his level 3 hyper combo from Marvel vs. Capcom: Infinite, Ultimate Strike, sending the target up and finishing with his buster.
 * Nova Strike appeared in Puzzle Fighter in a similar way to Project X Zone 2, X using it without his armor as his assist skill and with the Ultimate Armor as his super skill. In his super, Ultimate Nova Strike, X equips the Ultimate Armor and flies over the opponent with Nova Strike, knocking him down, and reappears from the top to smash the target with Nova Strike.
 * In Shironeko Project, X's X Strike skill is similar to the Nova Strike, with X rushing forward while surrounded by energy that makes his immune to most attacks and causes damage to all enemies in the path. X can freely change his direction during the move. The lower X's HP, the higher the damage X Strike will cause. X Strike also grants three buffs for X's attacks.

Other media
In the Rockman X4 manga, Ultimate Armor X unleashed the Nova Strike attack against Magma Dragoon during their battle to repel Dragoon's heat blast. X was successful in doing so and made contact with Dragoon, but Dragoon was able to ultimately pound X to the ground and strike him away.