Safe and Not Sorry is the first stage in Stairway to Darkness, sub-chapter 21.
This is the first level that Pigeon de Sable will appear in. When the level begins, only Snache and Pigeon de Sable will appear. Upon damaging the base, R. Ost, Mooth, and a large group of Pigeon de Sable will spawn.
CAT CPU IS NECESSARY
Crazed Gross Cat is pretty effective against the Pigeon de Sable; when the boss appears, the Pigeon de Sable must be defeated before it accumulated and using long-range character (Bahamut Cat and Ururun Wolf) to damage R. Ost and the Mooths behind it.
Cat Line Up:
Crazed Wall Cat (20), Gold Macho Cat (25), Mohawk Cat (33), Octopus Cat (30), Eva Unit-08 & Cat (19)
Use Crazed Wall and Octopus to stall the Pigeons and max out the Wallet. Do not use more than one Octopus.
Once the money is almost maxed, spam everything. The major threat is R. Ost, but Eva Unit-08 helped a lot by killing / knocking back the Mooths. I was thinking that Octopus can help me win the stage, but it can be killed by the R. Ost easily. Indeed, at my level, the R. Ost (1 Star) almost pushed to my base but I finally killed it before it did. A Sniper Cat may be helpful, though I didn't use one.
Strategy 3 (4 stars)
Power ups: cat CPU and sniper the cat
Catcombos: weaken combo and attack combo (i used firewatch and sister act)
Cat lineup:cat combos, samba cat (level 27), catburger (level 23), jiangshi cat (level 26+9), Paris cat (level 40+11) and magica cat (level 26+4)
Turn off cat cpu and sniper the cat, stall with one paris cat at a time while leveling up your wallet until you reach max money, then turn on cat cpu and, once you hit the base, turn on sinper the cat.
Sit back and relax.