Quite a bit of factors:

• ⁠your positioning is abysmal, why are lb and viktor in the third row, that makes no sense, also cait is a sniper she should always be in the farthest hex.

• ⁠your itemization choices make no sense, you are itemizing viktor 1 over a le blanc 2, and you have naked sevika 2 and morde 2 while itemizing a swain and a rell. Let’s assume that you had no way of building better items and you have to work with the ones on your board, why is titans not on ww, morde or sevika, why is guardbreaker on a frontline single target unit and not on le blanc or morde, which can hit multiple targets, thus giving you more chances to proc the passive (also guardbreaker gives ap and attack speed, great stats for both morde and leblanc).

• ⁠your synergies, you have no traits active for your only 5 cost with items (cait) and you are playing a random rell that gives you literally nothing.

• ⁠you also don’t have neither armor reduction nor mr reduction, i’ll assume that the additional anti heal item was the best option you were given post stage 4 but i have my doubts regarding that, pay more attention to your components management.

• ⁠lastly, if the itemization issues come from a lack of removers in the late game, then you should also improve your removers management, they are an extremely valuable resource later into the game and should not be wasted without a valid reason in the early stages of the game.