The trade-off is that you generally must commit a lot of resources to the Fusion Summon and you are also forced to play the listed materials which are not always strong enough on their own
The other modes and combinations are also effective, and all of that at instant speed too
Amulet of Vigor, Shadowspear, Colossus Hammer, Relic of Progenitus, just to name a few, are all very impactful artifacts which can turn the tide of a game
This special Black Star Promo blends history, rarity, and artistry, making it a crown jewel for any serious collector of Pokmon cards
If that wasn't strong enough, in conjunction with all the other Cat synergies you can create, you could pay three mana to double another Cat's power and give it trample when Arahbo is in play