Let’s just say I’ve spent a lot of time in Custom Battle Mode and I think I’ve earned my stripes here. I don't think there's much debate that the mode is very shallow as it exists right now.

This is everything I can think of to fix the mode so it can live up to its potential. Obviously it will also benefit from the general addition of more content to the game, so I'm not gonna talk much about that. I’m also not addressing any bugs. Bear with me:

General

• More efficient search mechanisms for character names, dialogue options, and switch word options.
• Ability to move and copy effect triggers across multiple effects tables (i.e., from A to B, B to C, etc.).
• Ability to “favorite” specific character names, dialogue options, and switch word options within a custom battle in order to create a shortlist of options relevant to that particular scenario.
• Option to group multiple custom battles together into a “Custom Series” for multi-part custom battles and relatedly to add “Part 1/2/etc.” thumbnail tags for clarity.
• Ability to freely customize character movesets from a set of selectable moves (think Raging Blast 2) as is featured in several Episode Battles.

Effects

• Ability to force Impacts (Speed, Power, and Crash) as is featured in numerous Episode Battles.
• Ability to force stage destruction (e.g., on Namek or World Tournament).
• Ability to toggle on/off “out of bounds” rules with an effect.
• Ability to apply Ki sickness as a debuff.
• Expanded trigger options for “Perform Action,” “Action Complete,” and “Attack (Hit/Miss/Block)” that are more responsive to particular gameplay mechanics such as Sonic Sway, Super Perception, etc.
• New trigger condition for “Win/Lose (Impact)”.
• New trigger condition for “Defeat (Out of Bounds)”.

Characters

• Ability to prevent player or CPU from switching into particular characters on the team (i.e., the reverse effect of the “No Switch-Outs” item) for purposes of including secret characters without preventing switching between other battle members.
• Ability to toggle on/off particular transformations on the character customization screen as you can currently do with Skills and Blasts and through effects.
• Costumes for guest characters with multiple different appearances.

Scenes

• Expanded 3D cut options including certain templates featured in 3D cutscenes in Episode Battle (e.g., in the screenshot below).

This is just one example, but you can see how these Episode Battle 3D cuts would vastly increase the available custom scenarios and allow for more dynamic scenes. There are a million of these shots in Episode Battle that seem to use the same basic mechanics as custom battle 3D cuts.

• Expanded use of existing 3D cut options on maps where they are not currently available (e.g., “Entry 1” or “Call Out 7”).
• Expanded 2D cut options.
• Allow the use of battle and guest characters’ audible Emote voice lines as dialogue options in Scenes.
• Allow the use of characters’ transformation animations as a 3D cut.
• Ability to adjust the Slow Motion Camera on Intro Pose, Victory Pose, and Super Attack 3D cuts.
• Ability to select different Super Attack cutscenes from a given character’s moveset in Super Attack 3D cuts.

Items

• Custom Battle mode would benefit from greater cosmetic item options being added to the game in general:
• Allow the use of Halo on all characters.
• Allow the use of Scouters on all characters (character models permitting).
• Add “Majin Mark” cosmetic item available for all characters except those who already have the mark.
• Add “Capsule Corp. Sticker” cosmetic item available on all Android characters with Red Ribbon Army logos (covers the RR logo wherever it is).
• Add “Watagash” cosmetic item available on all characters (honestly, idk why it popped into my head lol).
• Aura Change Blue/Purple/Yellow/Red/Green/White/Pink/Violet
• Aura Change Ultimate/Ultimate 3/Ultimate 4
• Restore missing items from Budokai Tenkaichi 3.
• Restore “Rugged Clothing” item from Raging Blast series which gives a character bruises and scratches and/or minimal battle damage from the beginning of a battle.
• “Reckless Blast 1/2/Ultimate Blast” item that gives a specified Blast attack the ability to cause map destruction when equipped. Does not work on Rush attacks.
• New “Aura Change” items with auras from Dragon Ball Super and others such as Android which were not featured in Budokai Tenkaichi 3.

Do I have faith? Not really. But with all of these changes put together we might have a salvageable mode here