Marco Po Road is the sixth stage in sub-chapter 20 of Stories of Legend, Silk Road.
The Enemy's Castle will spawn 1 continuous, clumped group of Doge, 1 group of about 6 Doge Darks, and 1 group of about 5 Gabriels. If you waste a long time stalling the Doges, they will spawn Gabriels instead of Doge Darks. After a certain amount of time, the order will shuffle and the groups will be produced faster and faster at smaller intervals, and basic Doge groups will no longer spawn, replaced by Gabriels. After that, the only thing that they will summon will be Gabriels. This continuous spawning plus a steady strength increase as the battle goes on makes this level very, very difficult, as many Doges will spawn and will be able to one-hit many of your cats.
If you stall for too long, the various Doge variants will increase in stats; Doge Darks will eventually increase up to 60,000 HP and 24,000 Damage and the Gabriels will have 78,000 HP with 9,300 Damage. On 2 stars, the Doge Darks will have 90,000 HP EACH and 36,000 DMG. The Gabriels will, in turn, have 117,000 HP; 13,950 DMG; you will need a lot of good ranged area attackers up fast without dying, while making sure you don't reach the cat limit and that you defeat Teacher Bun Bun before 3 minutes pass with extreme precision.
Any player lucky enough to have Kasa Jizo can easily destroy this stage by spamming said unevolved Ultra Soul.
After the enemy's castle health is dropped to or below 1,499,999 HP, the Boss will appear, Teacher Bun Bun. This Bun Bun will have a strength magnification of 900%, and while it is out, Doge groups will continue to spawn. After it is defeated, the Doge groups produce even faster than before due to the alleviated enemy spawn limit.
Be wary of the cat limit here, and never let the Gabriels reach your stack of attackers at any time or you won't make it.
The Gabriels and Doge Darks in this stage are more stronger than all the doge darks in Star Ocean Combined.
As SOON as the Teacher Bun Bun appears, fire the Cat Cannon. The Cat Cannon is normally no longer useful, but unless you fire your cannon at the right time, the Gabriels that are spawned with Bun Bun will charge through your meatshields and one-shot kill all of your units at once due to their area attack. Sometimes, if you are lucky, they will spawn Doge Darks instead, however, you should still be ready just in case Gabriels appear.
A useful strategy for this level would be to use cats with very strong area attacks or VERY high health, as the constant spawning of Doge Darks and Gabriels becomes very overwhelming if they are not killed quickly.
Cat line up: Crazed Cat, Mohawk Cat, Crazed Wall Cat, Eraser Cat, Paris Cat, Crazed Sexy Legs Cat, Crazed UFO Cat, Drama Cats, Crazed Bahamut Cat, Ururun Cat. Spam stallers, and Crazed UFO Cat as soon as the battle starts, as you can't afford to lose ANY time. Don't worry, the Gabriels/Doge Darks give quite a lot of money. Remember to fire the cat cannon as Bun Bun appears, and don't forget to keep spamming despite the 'Can't deploy any more' message.
There is an easy way to exploit the stage. If you send a Li'l Giraffe Cat the start of the battle, followed by Li'l Wall Cat spam. The spawned Doges would be blocked by the Giraffe and once the Wall Cats arrive, the Doges would not be knock backed by the Giraffe and would stay alive, allowing you to destroy their base by spamming the rest of your cats. Just don't use any long rangers and/or wave cats so you don't kill the doges behind the base, so this stage becomes a walk in the park.
This happens because of the enemy limit of the game, and the build up of the weaker doges, it "blocks" the stronger enemies from spawning, even the boss.