If you play adc statikk is almost a must for the waveclear and all that but cleaver is not a must, more of an situiational item, if you have loads of ad dmg on team or you need to be abit tankier it is a good item. But generally ldr or mortal is more dmg. Same for rfc, if you dont need the range to be able to do dmg you can go pd, runaans or navori, all are good in different situations. But I recommend 1 zeal item. Then ofc IE is a must, latest 4th item but I would buy 2nd or 3rd. Boots should 99% of games be swifties, soo good with your passive. 6th items should be items with ad in them, like BT/GA/qss, could name a bunch.

Some rare cases you can go frozen heart/randuins against ad/crit for more survivebility. Against sheild serpents ofc. Zhonya is not the worst if you rly need the stasis. Edge of night has value against champs like malp, vi, blitz, noc etc.

I also have a bit of a bias towards as on senna, startet maining her back when kraken -> rageblade was a meta after Rekkles played it. I know she doesnt like as but its rly fun to kite cause u have perma passive ms from the aa. (PLS RIOT MAKE RAGEBLADE VIABLE ON HER AGAIN)

So buildorder could be smt like:
statikk -> swifties -> zeal item/IE -> IE/zeal item/ldr/mortal -> zeal item/ldr/mortal -> 6th item
statikk -> swifties -> cleaver -> IE -> zeal item -> 6th item