If she ever dies, you get to put X +1/+1 counters onto each legendary creature you control, where X is the number of +1/+1 counters on Aerith
The card has also received a significant boost from the recent Team Rocket renaissance in the modern TCG, with the Destined Rivals and Glory of Team Rocket sets renewing mainstream interest in the original Team Rocket-themed cards from the Wizards era
In Modern, meanwhile, Dimir Murktide players are using Oculus and seeing results
Neither player takes any battle damage from that battle, also, after damage calculation, if any player's monster would be destroyed by that battle, send all cards that player controls to the GY instead
What affects the value of Magnemite
You generally get at least one trigger, plus it opens the door to really interesting synergies with cards like Nesting Dovehawk and Padeem, Consul of Innovation that affect themselves when converted into tokens or artifacts