Played against an infamous Korean fleet in the CN server that loves imitating renowned Chinese players such as DDT or KlunKI, or even my youtube videos... (I was also told that sometimes they claim to have designed their own unique boxes or hero builds after blatantly plagiarising -ㅅ-) This was why I could predict the boxes and the play style of the opponents in the match. Fortunately, I also have already played against this account several times in the ranked mode prior to this match and knew they were ultimately playing passively (this is also clearly shown in the linked video above: stiff and reluctant to do DPS exchange...). The opponent chose to use Baldr (in the previous matches, including the one in the link, he chose to use Heimdall, even in situations where he needed high physical damage) and this has tremendously lowered the AOE damage dealt by Leon in the first match. Leon was too much giveaway and was used recklessly as he could not return within Landius's guard range after the AOE (also failed to launch a combo with Kayura). The second match was straightforward, as the BP and playstyle stubbornly persisted being passive and let me chose Oboro.
The opponent might have had better chances of winning should they have played bit more actively (and patiently, especially during the first match because I did a poor BP as well), since the box and hero builds weren't shabby at all.