Im sure itll spawn its own Commander decks down the line but stick with Caesar out of the box
Protection only prevents damage from the sources your permanent has protection from
After all, his ability doesn't trigger off creatures entering, only from casting them, so you don't get to double up his triggers when you use Ashling to make token copies
Many of the best Pokemon TCG Pocket decks feature two things to take note of
Cards like Bloodtithe Harvester have a limiting phrase that reads something like activate only as a sorcery. When Can You Use Card Abilities
There are many other rare cards to collect including: 236 total reverse holos, 20 Art Rares, 9 Secret Rares, 10 MEGA Attack Rares, 17 Special Art Rares, and 1 Mega Ultra Rare