What Diana stands out the most is how in a trade she can do a lot of damage to the enemy team if she makes a mistake by positioning herself poorly or making a pick without vision since Diana's ultimate is very strong.

The character is strong to play solo or in a team:
1) Diana in a team has a very marked role, Bursting the ADC or the squishy carry / Being the entry of the tf.
Diana has enough damage to be able to burst any squishy in the game, especially the ADC'S, and playing Diana Conqueror is one of the best fronts there is, thanks to the fact that she can win almost all the 1 vs 1 trades alone.
2) Diana to play solo is to have the role of an assassin, you always have to go looking for picks or be in places where they don't have vision (Bush) to be able to burst the one who is unaware. Above all, going full damage can turn around a fight that was lost.

Diana in lane runs out of mana very quickly online, not knowing how to minister to her can make you back a lot or believe you have mana for trades and die because of it

Diana is very easy to gank, especially if the enemy team has a lot of CC. Once Diana trades, she is very sold out and the enemy jungler has a free gank to kill you.
(You have to ward a lot to see where the jungler is and be able to trade when he is far away)

Playing Diana entry has its big disadvantages, above all is that if your team does not follow your play, you will probably be left exposed and the enemy team will look for a fight where you are not and be greater in number.

Diana loses very easily against characters that have a pretty good level 2, let's take the example of Talon. Diana can't trade him because Talon will win in every way, and will always have a higher push than her.

The best trade for targeting can be at LVL 2 applying the passive, Example:
Q+E+AA(Charged Passive)

You can throw the E without needing to hit the Q, when an enemy is at low health, normally they would wait for you to hit the Q and then dash, but if you throw the E first they will get scared and flash where the Q will give you the range to kill them with that

Remember that the damage of the W also makes a change, when you can try to throw it.