No, Mega Evolution cards are not good for beginners, as they involve higher-risk gameplay mechanics and are no longer part of the Standard format, making them better suited for collectors or experienced players.
If you were to lose due to poison counters, you would immediately lose as soon as the ability resolves as you still have 10 poison counters
Damage wears off, and "this turn" and "until end of turn" effects end.) At the beginning of your next end step, you lose the game
What you get instead is the ability to send a wave of damage at any target when it enters
Youll want to ramp out basics via Rampant Growth and friends, so youll naturally avoid an artifact-heavy mana base, giving you access to disruptive tools like Collector Ouphe and Null Rod
Also, Im not a huge fan of poison, and dont exactly want to see it overrun the format