For first two, buy recipe again IIRC.

BKB I not sure.

BKB only can re-buy whole thing

Drop the bkb and rebuy a new bkb.

I'm not sure about the diffusal blade though.

BKB cant sold and cant get back 10sec sekian

Yes, diffusal need buy everything again.
BKB can be dropped ?
True.

Ubah at Dota 

ilussion deal damage based on the main attribute not raw damage, so if u buy item like radiance, divine rapier, the ilussion wont deal those damage, so the idea of armlet is activate ur armlet before u use ulti, then ur image will be much stronger. 1st and 2nd skill is very important to me, can kill heroes easily, since early game ur damage still very low, the chaos strike damage wont be very effective. this is my opinion.

^CK has good starting base dmg IINM. Only problem is his atck speed, hence Wisp/CK strat (I think)

Always up first and second skill, skip Ulti until level 10 and 11. Getting it at lvl 9 is kinda pointless because one illusion is not that good. So lvl 9 get one level of your third skill but always max your first two skills.

Item-wise, get items that boost your atk speed, like Drums, Yasha and Armlet. Rush Armlet after you get Drums or if you're winning your lane, rush Armlet straight. After Armlet you can freely pick either Manta or go straight Heart (with Heart, you can turn on Armlet 24/7). I reckon Halberd is pretty good with the evasion bonus.

Always toggle on Armlet before using your Ulti as your illusions will get the Armlet buffs.

With red text? If it is then its worth nothing.. Can give out for free.. If not then can trade for keys 

This is a restricted gift which can not be redeemed in these countries: China