In Yu-Gi-Oh Duel Links, extra link rules are not adopted, so extra link itself is impossible
Here are all the cards you need for 'Celestial Guardian's Museum 2': Alolan Exeggutor #156 (Full Art / One Gold Star) Morelull #157 (Full Art / One Gold Star) Alolan Marowak #160 (Full Art / One Gold Star) Turtonator #161 (Full Art / One Gold Star) Alolan Vulpix #162 (Full Art / One Gold Star) Pyukumuku #163 (Full Art / One Gold Star) Tapu Fini #164 (Full Art / One Gold Star) Tapu Lele #170 (Full Art / One Gold Star) Cosmog #171 (Full Art / One Gold Star) Minior #174 (Full Art / One Gold Star) Pikipek #177 (Full Art / One Gold Star) Bewear #178 (Full Art / One Gold Star) Rewards: 12 Pack Hourglasses, 36 Pack Wonder Hourglasses and 10 Shop Tickets
Most notably, it means he's pretty much an automatic inclusion in an Ezio deck - and this is the other breakaway commander from the set, with more than 2,500 decks logged so far
This Rakdos commanders a 7-drop, so theres time to prepare, but the few Kaervek players out there probably run it alongside cards like Havoc Festival and Descent into Avernus
But thats graded at a 10, which is extremely important