A new Slime monster with zero ATK that can easily be Summoned and bump its Level to 10 for Egyptian God Slime is the best way to do this, especially if the Slime monster in question has an effect that lets its owner search and/or mill an Egyptian God or one of their support cards
Well it's certainly got a mighty effect
You can only use this effect of "Trishula, the Dragon of Icy Imprisonment" once per turn
All the best trainers, however they started out, lost their fair share of battles

Ragavan, Nimble Pilferer : Around $600 Atraxa, Praetors Voice : Around $650 Elesh Norn, Grand Cenobite : Around $550 Jin-Gitaxias, Core Augur : Around $340 Skithiryx, the Blight Dragon : Around $450 Lurrus of the Dream-Den : Around $385 Yorion, Sky Nomad : Around $290 Yarok, the Desecrated Halo : Around $300 Sheoldred, Whispering One: Around $325 Kenrith, the Returned King : Around $340 Horobi, Deaths Wail : Around $335 Thalia, Guardian of Thraben : Around $340 Jegantha, the Wellspring : Around $240 Teysa Karlov : Around $300 Kroxa, Titan of Deaths Hunger : Around $350 Gyruda, Doom of Depths : Around $210 Baral, Chief of Compliance : Around $220 Kaheera, the Orphanguard : Around $230 Seizan, Perverter of Truth : Around $200 Obosh, the Preypiercer : Around $150 Brudiclad, Telchor Engineer : Around $210 Tetsuko Umezawa Fugitive : Around $200 Emry, Lurker of the Loch : Around $210 Keruga, the Macrosage: Around $150 Grimgrin, Corpse-Born : Around $155 Goreclaw, Terror of Qal Sisma : Around $135 Juri, Master of the Revue : Around $140 Arixmethes, Slumbering Isle : Around $175 Squee, the Immortal: Around $140 Lutri, the Spellchaser : Around $125 Dina, Soul Steeper : Around $150 Taigam, Ojutai Master : Around $140 Ayara, First of Locthwain : Around $145 Lathiel, the Bounteous Dawn : Around $145 Ezuri, Claw of the Progress : Around $130 Yargle, Glutton of Urborg : Around $120 Sram, Senior Edificer : Around $115 Firesong and Sunspeaker : Around $110 Inga Rune-Eyes : Around $100 Most expensive MOM Japanese gold-stamped signature tokens Available from April 14 to Aug

Not only do they allow us to get the gravestorm needed to kill with our Bitter Ordeal / Psychogenic Probe combo but they also clog up the battlefield against creature decks while we are waiting to find our combo pieces