This is a great way to dip your toe into the water if you aren't sure the Prerelease is something you want to do or if you can't commit 5 hours to a Prerelease event
It can't block as long as it has a +1/+1 counter on it.) : Regenerate this creature
Speaking of difficult to deal with, the announcement also bans the cards Fires of Invention and Agent of Treachery from the Standard and Historic formats
There are lots of options for sure
Without black in her color identity, Aerith most closely resembles Celestine, the Living SaintCelestine, the Living Saint from the Warhammer 40K Commander precons, both for how they weaponize lifegain and operate within a limited pool of janky nonblack graveyard enablers
Crucially, it also spreads this protection to every other Dragon you control, making board wipes the only real option for dealing with your winged arsenal