Hi,

fiendhunter bolts scales directly with critical strike chance in order to access the true damage more reliably. Keeping in mind the enemy team comp you were against, kraken slayer doesn't achieve its main goal which is to do % hp missing damage bonus every 3 attacks as the opponents will have high hp + high healing and ways to slow down your dps.

Swain has massive sustained healing and lee sin can heal a lot with his w and if he opts into healing items as well.

Blade of the ruined king is your best bet of applying meaningful dps into opponents as they will be naturally buying health items and be higher level than you giving them more bonus health. as with yunara you can't exactly ignore the front line in this instance so it really is a must buy. the 2nd item can be flexed but keep in mind you need an early executioner's calling in order to cut their healing significantly.

the options of the 2nd item is phantom dancer, fiendhunter bolts, runaans. With the team you are against I feel you may end up being the focus and as they are 3 melee champs + a slow moving swain into you I would look to potentially buy runaans hurricane 2nd to apply blade of the ruined king effect on 2 other targets.

Phantom dancer for raw stats definitely wins out but watching how enemies play before you get such items can help you determine how to play it out.

Fiend hunter bolts we acknowledge needs time to scale in for true damage dps so I would say this to be the least likely option in this instance.

Hope that was somewhat helpful!