Serenade.EXE

Serenade.EXE (セレナード), also known as "S" and "UnderKing" (however, in Japanese version, Serenade is female), is a NetNavi from MegaMan Battle Network 3, and is the ruler of the Undernet. When Lan is asked to obtain the Forbidden Program called "GigaFreeze", which is able to freeze Alpha in case it awakens, he goes to Undernet and has to defeat several ranked Navis to reach "S", the rank 1 Navi that protects the program. After defeating rank 2, MistMan (White version) or BowlMan (Blue version), he discovers the Navi is called Serenade and is located in the server of the Undernet. MegaMan finds the server in the Ura Inn, where Serenade's voice can be heard and says that if he want the Forbidden Program, he must be a "Chosen One" to hold it, or the program would freeze him forever. MegaMan is able to take it and leaves, and Serenade is surprised to see that other Navi is able to hold it. Later, MegaMan tries to use the program against Bass when he was taking Alpha after DrillMan's defeat, but it sees he is the other "Chosen One" mentioned by Serenade and is able to stop the program.

It's believed Mamoru is Serenade's operator, as he has Serenade's emblem on his wheelchair, and his father created the Undernet.

After completing the game and completing other quests (like defeating Beta Navis and collecting all normal BattleChips), the player can enter in a Secret Area from the Undernet server, where he fights against DarkMan and JapanMan before meeting Serenade. Serenade recognizes MegaMan's power for being able to defeat JapanMan and DarkMan, and says the source of his power is mercy, and he wins because he loves and respect his enemies. After defeat, Serenade reveals he fought against Bass in the past, winning after a battle that last days. MegaMan receives Rank 1 and a side-quest will be available after logging out and them returning to the Secret Area, a time attack against several Alpha NetNavis with a Extra Folder. The player can obtain the BattleChip Serenade S (White version) or DarkAura A (Blue version) if a new record is set in all Navis.

Abilities
Serenade is extremely powerful, he's even said to have even defeated Bass in the past. He possess a massive amount HP (the same as the normal version of Alpha). Serenade possess the ability to knock back any attack as a deadly Sonic Boom. It always does the same damage, regardless of how strong or how weak the attack was. This ability makes Serenade impossible, except for when he uses his Holy Shock, an energy attack that can hit any two panels, or by stealing all or his panels because he has to move to use his Sonic Boom. To hit him, one has to anticipate when he's going to use Holy Shock. Serenade's primary attack is Saint Light, where sends a ball of energy the moves up and down while moving left, and will keep moving until it hits something or reaches the end of the screen. This attacks moves slowly and easy to dodge.