But if you're thinking the card has actual power when played in a game, think again
If youve been playing since day one, chances are, your in-game collection has probably filled out pretty nicely
Unless a card says otherwise (like Rat Colony) or it is a basic land, you cannot put more than 4 copies of the same card in your deck

Ashcoat of the Shadow Swarm Ashcoat of the Shadow Swarm Azure Beastbinder Blightbelly Rat Bog Rats Burglar Rat Carrion Rats Chittering Rats Chittering Skitterling Crypt Rats Daggerfang Duo Deathmask Nezumi Dirty Rat Dirty Wererat Disease Carriers Diseased Vermin Drainpipe Vermin Earsplitting Rats Elephant-Rat Engine Rat Freya Crescent Gnat Miser Gnawing Vermin Gobhobbler Rats Graf Rats Greasefang, Okiba Boss Gutter Skulk Hellhole Rats Hideous Fleshwheeler Ichor Rats Infected Vermin Ink-Eyes, Servant of Oni Innocuous Rat Insatiable Frugivore Karumonix, the Rat King Kuro's Taken Lightshell Duo Locust Miser Lord Skitter's Butcher Lord Skitter, Sewer King Marrow-Gnawer Mind Drill Assailant Mindwhisker Muck Rats Mukotai Ambusher Nashi, Moon Sage's Scion Nashi, Moon's Legacy Nashi, Searcher in the Dark Nezumi Bladeblesser Nezumi Bone-Reader Nezumi Cutthroat Nezumi Freewheeler Nezumi Graverobber Nezumi Informant Nezumi Linkbreaker Nezumi Prowler Nezumi Road Captain Nezumi Ronin Nezumi Shadow-Watcher Nezumi Shortfang Nightwhorl Hermit Okiba-Gang Shinobi Old Flitterfang Ossuary Rats Pack Rat Persistent Marshstalker Pestilence Rats Plague Rats Rabid Rats Rancid Rats Rat Colony Rat King, Pale Piper

To be honest, I would've seen DIVINE as a ritual archetype, but if you want an Extra Deck, Fusion is definitely the way to go
Abby, Merciless Soldier Partner is generally a good ability to have and the one I think Abby, Merciless Soldier works best with is Joel, Resolute Survivor which makes great use of the tokens you get from casting Abby