Bernstein

Magic Resistance. The pseudodragon has Advantage on saving throws against spells and other magical effects.

Improved Critical. Bernsteins attack rolls score a critical hit on a roll of 19 or 20 on the d20.

Multiattack. The pseudodragon makes two Bite attacks.

Bite. Melee Attack Roll: +6, reach 5 ft. Hit: 4 (1d4 + 3) Piercing damage.

Sting. Constitution Saving Throw: DC 13, one creature the pseudodragon can see within 5 feet. Failure: 5 (2d4) Poison damage, and the target has the Poisoned condition for 1 hour. While Poisoned, the target also has the Unconscious condition, which ends early if the target takes damage or a creature within 5 feet of it takes an action to wake it.

Second Wind. Bernstein can use a bonus action on its turn to regain hit points equal to 1d10 + its level in this class. Once it uses this feature, it must finish a short or long rest before it can use it again.

Martial Role Defender. Bernstein can use its reaction to impose disadvantage on the attack roll of a creature within 5 feet of it whose target isn't the sidekick, provided the sidekick can see the attacker.