Sometimes you have to fight fire with fire...or in this case, venom with venom.
Spoilers incoming for Batman/Teenage Mutant Ninja Turtles II #4 and #5, so if you haven't read the issues yet you've been warned.
The turtles find themselves in a brutal fight with Bane and his army, and while they put up a strong showing, Bane eventually gets the upper hand and is about to slam Raphael over his knee (just like a certain Dark Knight) when Splinter interferes. Splinter manages to dodge his attacks for a minute but eventually gets taken down.
The Turtles retreat and get Splinter to safety, but Donatello feels incredibly guilty over causing this in the first place. He brings up possibly using Bane's Venom to fight back, but while Raphael supports his decisions, the others aren't on board. Donatello does it anyway though, creating a Venom rig of his own and injecting it, which bulks him up considerably.
He then takes out a huge group of Bane's army by himself, going from hideout to hideout and knocking them off one by one. Unfortunately, it isn't all good news.
In #5 though he learns that while the Venom increases his bulk and strength, it also fees into his anger and rage, and makes him, well, a bit hard to reason with. Batman and Leonardo do their best but it isn't until they make him realize they need his mind, not his muscles, to take back the city.
You can check out the spoiler images in the gallery.
Batman/Teenage Mutant Ninja Turtles II #5 is written by Ryan Ferrier and James Tynion IV with art by Freddie E. Williams II and Jeremy Colwell. The official description is included below.2comments
"A Venom-charged Donnie wages a brutal, one-Turtle war on the Foot Clan. Batman has to stop him and remind him of who he really is; someone who uses smarts—not brawn—to take down the bad guys. Damian and Raphael pay a visit to the Lazarus Pit to try and help a wounded Splinter. Then Batman tries to turn a former foe into an ally as part of a desperate attempt to finally end the reign of Bane."
Batman/Teenage Mutant Ninja Turtles II #5 is in comic stores now.