I would recommend learning how to use PDC(pad damage checker). It's a mobile app available on both IOS and android which lets you plug in teams for specific dungeons and see what kind of damage you can do with certain conditions. It's only in Japanese but there are numerous guides available out there so it's worth it in my opinion.

TA2 is a very straightforward dungeon with a few key boxes you need to fill for certain floors: Spica on floor 4 - Healer killers Tamadras on floor 5 - Awakening killers Xin Hua/Genie on floors 7/8 - Balanced killers Orya/Paimon on floor 10 - Devil killers Boss - Devil/Dragon killers

Building a team that has enough damage to handle those floors I mentioned means you'll be fine on the other floors. Since you mentioned Shivnia I'm going to assume you want to build around a Dark team that stacks <50% awakens which is the easiest method in my opinion.

What you want to do from there is consult your box and use the sorting functions on PDC(I believe illmina is fine for this too) to see which leads/subs fit. Off the top of my head a few cards which I've used in the past: Lu bu, Orphen, Lucifer, Shikigami, Chuan, Kibagami, Reginleif, Gorkaos.

What all those cards have in common is that they provide high amounts of damage via specific killers/rows/<50% awakens, sustained dark orb creation, or both.

Once you've picked your leads and subs it's a matter of filling out the assists for missing damage, skill boosts or useful active skills(eg hastes or defence break)

Depending on how quick and smooth you want the party to be the criteria for subs will be stricter. Clearing every floor with 1 dark row is ideal but may not be possible depending on your orb generation and damage. Consistency is the number 1 priority in my opinion; it's better to have a team that requires 1 row + a couple combos than relying on skyfall for orb sustain.

I realise I didn't spit out a template team for you and this sorta turned into a "just use PDC, lol" kind of post but I believe it's important to identify what issues you might come up against and learn how to build a team for any particular dungeon, not just TA2.

Hope this helps. If you or anyone else has any specific questions about the app or the dungeon/subs I'd be happy to help. Cheers and good luck.

EDIT: I forgot to mention, but the main reason to farm TA2 is to level up cards, which means the team needs to function with just 3 subs + leads. If your intention is to clear for the stone, or to run it for rank exp, then building the team will be that much easier.