Bit of a WIP, but the stratagems are just a proof of concept.
For Super Earth. For the Erdtree. Bring Helldivers 2's stratagems into the Lands Between.
Hold Left Ctrl (controller: hold View) to open the stratagem list. Then punch in the real Helldivers 2 arrow codes with W A S D or the arrow keys (controller: D-pad). After the call-in time, the strike lands about 12 m ahead of your Tarnished.
Stratagems
Helldivers 2's side: the stratagem input beeps, each strike's impact sounds and the Eagle pilot's radio calls come from your own Helldivers 2 install. Stratagem Ring reads them from your Helldivers 2 folder on the first start, which takes a minute or two. Nothing from Helldivers 2 is shipped.
Elden Ring's side: the blasts are Elden Ring's own fire pots, giantsflame, volcano pots, ancient dragonbolt lightning and Erdtree Heal. They're yours, so they hit enemies and not you. Every stratagem has a cooldown, shown on the list.
You need Elden Ring and Helldivers 2 installed on Steam. It plays offline in single player: Melty starts Elden Ring through Mod Engine 2 with Easy Anti-Cheat off.
Credits: Mod Engine 2 (soulsmods, MIT), filediver (xypwn and contributors, BSD-3-Clause), MinHook (Tsuda Kageyu, BSD-2-Clause), bullet names from soulsmods/Paramdex. Fan-made, not affiliated with FromSoftware, Bandai Namco, Arrowhead or Sony.