Edit: DLC categories need more support before they can be added. Please leave a reply if this interests you!

DLC categories could be a good addition to spice up the leaderboards since there's only 3 categories right now. The Traditional Beauty outfit is quite OP compared to every other outfit, so it'll be interesting to see how these categories develop using other outfits.

Only currently released DLC should be allowed. Note that there is a PS5-exclusive DLC outfit - the Toro Hat. But it's probably not good anyways since it's just Draw 4 Cards if all spells + Shishinoshin badge.

Categories:

Mirror World NG+ (DLC Characters):

The interesting thing about this one is that the final boss is CM Yohane instead of the Mirror. The potentially good characters are You (+1 atk, def, draw) and Chika (+1 energy). DLC characters also have access to a new Yohane summon, with CYaRon's being +2 Energy and +2 Draw.

Mirror World NG+ (DLC Outfits):

Nightwicked Night is probably the best outfit; it gives +2 energy when HP <30% and lets you spend 2 HP to fade a card. There's also an outfit to reduce shop prices and one that starts with Dragonfly Return, a pretty good attack card.

Any% (DLC Outfits):

tbh i don't really care about this, but you can add this so we have comprehensive DLC categories

Suggestion 2: Run Variables

Another great way to introduce variety to the leaderboards is Run Variables. When submitting a run, you now specify which Deck Type (Bal/Power) and which Character (DLC only). If runners submit 2 runs with different Deck Type or Character, they should both show up on the board (I believe this is possible on SRC by making variables not obsolete each other). This would incentivize people to try different run styles/characters that are off-meta. I don't think outfits should be one of these variables because they can be very similar gameplay-wise, and this could lead to leaderboard bloat. DLC characters on the other hand have more unique effects, and it would be nice for each character to have representation on the leaderboard, since they are so beloved by fans.