Here is a quick guide on ROM latest event Tokyo 3. To begin, go to Prontera and find Rei Ayanami, she is standing near the Auction House.
The event requires you to have a party, recommended party is 5 including yourself. It doesn't matter which class. The rules is to clear the dungeon, the faster, the better.
The dungeon consist of 3 Angels, and they need to be defeated, every Angel comes with different trait, so you need to change your Eva accordingly to defeat them.
The available Eva are Unit-01/Violet and Unit-02/Red. These suits can be changed during the battle, take not changing suits has long cooldown. Use it wisely.
You don't need to switch Suits every now and then, let the 4 party to stick to their color; example, 2 party will be red and 2 will pick violet. The 1 party will be the switcher, that means, he/she will switch depending which Angel their fighting.
Each suit has their own benefits to the party, Red deals damage and Violet provides support which gives more damage to the party. It doesn't matter which suit you will pick, but a recommended setup is to a have a violet suit. It could be 3 Red/2 Violet or 4 Red/1 Violet. Red suit should spam their second skill only.
First Angel, can be damaged using Red suits, and Voilet should use the 3rd skill, a buff skill. Recommend: 2 Red, 3 Violet, buffs stacks and will deal more damage to Red.
Second Angel, can be damaged only using Violet. Recommended: 2 Violet, 3 Red.
For Third Angel, you need to switch into different suit. Recommended: 2 Red, 3 Violet when HP is <50% switch to 2 Violet, 3 Red.