In My Opinion: The following champs are op, strong, and need a look at/ Rework
OP:
Darius is to strong early game and snowballs
Kalista E needs to be nerfed
Nasus Does damage for farming. The basic thing you do in league
Yi is the biggest JG Hyper carry next to udyr
Shyvana level 1 W is half of my HP bar gone
Trynd Doesn't even need abilities since he crits and does 250 dmg with an auto att at level 2
Xin does too much damage and he builds tank.
Strong.

Vlad has a strong late game Viktor's laser can one shot people with his shield Olaf and True damage..... Naut IS the CC KING Jax is almost as bad as trynd Gragas does too much burst dmg Alistar is cc dominate support

Redone/rework. Poppy looks like the 2009 days of league. She needs REWORK and VISUAL UPDATE. Quinn is the laughing stock of ADC Kennen hasn't been changed since like season 2 Galio is the champ we all forget exist Zyra is obsolete now.
All these champs need to be looked over. Also, Graves needs a cigar,