Are Tamed Monster Growth Patterns Random

Omega is a COM with Late Bloomed (i.e. max level 99), Sparkprone, and Heartless.

Passives Abilities: Feral Surge, Feral Fatigue and Leadenstrike.

Starting Attributes:

Attack 595
Magic  479
ATB    Level 3
HP     3241

Chocolina stops selling the potent monster materials after the first grade. She does, however, start selling Power Orbs, Mana Orbs, Vitality Orbs when you get to Academia -500 AF-, but that's towards the end of the game.

Here's where you can farm the materials:

Potent orbs

• Buccaboos in the Stonestump Wastelands and Grave Ridge areas of the Archlyte Steppe -??? AF- when it's sunny
• Ghouls in Academia -400 AF-, but only before you reach New Town²
• Garganzolae and Apotamkins in A Dying World -700 AF-¹
• Winning the Orphan Derby, Lindzei Cup, or Pulse Cup in the Fal'Cie class Chocobo races at Serendipity -??? AF-

Potent engines

• Flans in Augusta Tower -300 AF-, but not on Floor 13
• Munchkins¹ in the Bresha Ruins -300 AF-

Vitality orbs

• Miquiztli in Academia -500 AF-
• Vodianoi and Samovira in the southern portion of the Grave Ridge region in the Archlyte Steppe -??? AF- when it's cloudy
• Bunkerbeasts in Yaschas Massif -100 AF-
• Green Chocobos in the -1XX AF- eras of Yaschas Massif
• Winning the Atomos Derby¹ in the Fal'Cie class Chocobo races at Serendipity -??? AF-

Vitality engines

• Zwerg Metrodroids¹ in Augusta Tower -200 AF-

Power orbs

• Tonberries that appear in rifts in the Brescha Ruins -300 AF-
• Buccaboos in the Stonestump Wastelands and Grave Ridge areas of the Archlyte Steppe -??? AF- when it's sunny
• Pitterpatters in Yaschas Massif -100 AF-
• Barbed Specters in the Stonestump Wastelands and Grave Ridge areas of the Archlyte Steppe -??? AF- when it's cloudy
• Winning the Carbuncle Classic¹ in the Fal'Cie class Chocobo races at Serendipity -??? AF-

Power engines

• Yaksha and Yakshini¹ in the Vile Peaks -010 AF-
• Shaguma and Haguma¹ in the Vile Peaks -010 AF-

Mana orbs

• Xolotl in Academia -500 AF-
• Sahagin Princes in the Assembly Area region of the Sunleth Waterscape -300 AF- after completing the main story events
• Winning the Anima Stakes¹ in the Fal'Cie class Chocobo races at Serendipity -??? AF-

Mana engines

• Vespid Solders¹ in Augusta Tower -200 AF- mostly on the 51st floor

^{Note 1:} My personal farming recommendations: they tend to have far better yields or are more mindlessly farmable than the alternatives.

^{Note 2:} They'll show up again if you close the gate.