To start, his first auto ability is one that activates when he enters the field: When Shinryu enters the field, deal 10000 damage to all the Forwards of cost 3, 6, and 9 opponent controls. Theres a restriction on the targets, but 10,000 damage is high, and it would generally be possible to break most Forwards meeting the cost conditions
That includes card removal, abilities like 'Rush' that let cards challenge faster, and big, beefy glimmers that hit hard
Sapphire Sapphire glimmers are intellectual, intelligent, and creative according to the brochure
Morph, Space Goo Emerald is already considered one of the best colours to play if you like using Lorcanas Floodborn Shift mechanic, which is the ability to play character cards for cheaper by putting them on top of a character with the same name that you already have in play