how to defeat renji

[Is this aura?]

his bankai is too powerful please help!

[Shayera_ZF]

just shield until it goes away

[Susi_Meow]

The trick to beating Renji is that he has no ability to win by taking 2 health bars, he has to take 3. Most good Renji will try doing this by 2,2,5.

Use this to your advantage by trying to awaken before you take his first and reach sublimation before you take his second. This lets you take 4 stocks then 5 stocks for the win before he can Bankai with most characters. Use your Reverse at the start of the match to White reverse. White reverse as often as you safely can to reach these stages as fast as possible.

Characters with resurrection are counters to Renji also, like Ichigo (Bankai) since his 2,2,5
will activate their resurrection once they have access to it and leave Renji in weakened state for the rest of the match. Renji has to kill these characters 4 times if he cant beat them before they reach Reawakening.

When Renji is not in Bankai just look out for his Special flash and get used to reacting to it with your Quick attack when you see him jump. They will try use this a lot as its plus on block but will always lose to your quick attack if you time it right.
When in Bankai abuse your flash step and any invincible move you have just to try an waste time and hold block, the timer is pretty small and if you can waste even just a few seconds he might not have enough to get the kill. Blue reverse is great here also as it gives you passive guard restoring, which can really slow him down.