User blog comment:Linathan/Unit Spotlight: ティルフィング (Tyrfing)/@comment-24506549-20150322003541/@comment-26140304-20150322010113

Definitely Melchio. Melchio has a 6*, which means he has SBB. He also provides a lot more utility compared to Tyrfing, especially status immunity with his SBB. Tyrfing, however, has very low stats compared to Melchio and can barely survive hits, especially from Trials and GGC.

Though, once you get further into the game with the new 7* units, you would want to use better Light units than Melchio in my opinion. In terms of elemental changing, use Shida if you have him. He provides all elements to attacks and boosts all other allies' BB gauge by 10 BC, which is the best boost in the game right now.

Hope this helps! :D