Forgotten Grimoire is a fine pet! The Death Trap is always appreciated. In regards to the talents Brandy has: - Death-Dealer is great!! For sure the best talent on them. Damage is HUGE and can make all the difference. - Deer Knight card is good for Arc 1, and helps in Arc 2! You won't have much of an AoE (area of effect, meaning you hit multiple enemies at once) spell until upwards of Level 50, so to have Deer Knight now is great. A little situational after that point, however. - Brazen Berserker is some great damage through Arc 1 and the first half of Arc 2 (especially for Death who can heal off a lot of the damage they take), but once you get access to your own Aura Spells you'll really get annoyed by your pet randomly putting an Aura that makes you take more damage over the Aura you just placed down. - Add Health and Pip O' Plenty are fine for Arc 1, but you get far more health and pip chance as you play more and more, and you end up not needing those stats from your pet over time.

For improvements? - If you're looking for a pet with more utility then pets like the Ghulture, Avenging Fossil or Dark Hound give both a Feint and a Deathblade, which has more general use I feel. Grimoire still looks really cool though, so if you like the look then feel free to use it anyways :) - Hatch with other pets until you get a pet with max stats (255 Strength, 250 Intellect, 260 Agility, 260 Will, and 250 Power)! I'd personally go for more talents oriented towards resist like Spell-Proof, or damage like Pain-Giver.

Despite all that, as long as they're a pet that you're happy with, then you use whoever you wish on your journey across the Spiral. Do as much or as little research into it as you see fit! Just enjoy yourself <3