How's this build on Kalista amd Twitch?

Yommuu, Runnan, LW -LDR, IE

Seeing as her early game is tough, bonus AD from Serrated Dirk would help her if she E's an enemy.

Yommuu's active is a fantastic compensation for when she's solo.

Runnan because it's Kalista.

LW to synergize with Yommuu. Woulda put Bork here but LDR is too good. Bork could be able to work here.

And an IE or LDR if you got bork to round off the damage.

Would suggest Warlords + 1 or 2 dorans for lifesteal. Late game lifesteal could be warlords + red pot.

One spot left for defense/offense item of your choice.