Celtic Guardian didn't have the stats to compete, and never really got a ton of great support to make it worth using later, either
Pokemon Card Strategy: So as far as strategy goes, since Alolan Golem is a Stage 2 Pokemon card, you'll first have to get Alolan Geodude into play and then evolve it into Alolan Graveler before you can evolve Alolan Graveler into Alolan Golem, both of those Pokemon are from this set and I've reviewed both of them the last two days
I wrote about what constitutes a Bracket 2 Commander the other week, and if theres one headline from that article, I believe that Bracket 2 works best when Commanders choose from mana advantage, card advantage, and win condition, and dont try and cram as many of them as possible into the zone
Rillaboom Secret Rare ($14-18) You ought to get special treatment when youre one of the three starters, and Rillaboom is probably the most unique in Sword and Sheild
For example, if one player has 10 life and the other has 17 life, the first player gains 7 life and the other one loses 7 life