Assuming you mean the .454 Casull, it can be very versatile. Ruger’s Alaskan fires both .454 and .45 Colt. The .45 Colt can be had in as many configurations and power levels as a .44 mag, including light loads such as are used in Cowboy Action competitions. Take the Alaskan to a qualified gunsmith and it can be machined to also accept .45 ACP in moon clips, added further versatility and ammunition availability.

Are by lever action, you are referring to a Model 94 or 336? If so, IMO a rifle in .308/30-06 class that allows the use of spitzer bullets would cover more possible uses. I prefer bolt guns. Don’t disagree on the .22 or 12 gauge but if I could only take one, it would be a 30-06.