I've been playing on my warlock for a very long time and as a class that specializes in all demonic arts I find it quite restricted with just 4 pets (+ 2 enslaved ones).
So I came up with an idea (well not mine but rather from another small game from the 90's).
Here goes;
Basically there's a lot of demons out there. My idea involves creating a new soulstone (not the existing one but rather a new soulstone. Let's call it soulcrystal to avoid confusion). We make it cost like 1 soulshard.
This is used to capture the soul of another demon (mobs in world or dungeons; basically anything you enslave). To make it not so easy to capture one's soul, let's go with a weakened demon (e.g. only able to capture if the health is at or below 25%). With the soul of that demon stored inside your soulcrystal you can keep it indefinitely (let's say the same as spellstone/firestone).
Now for the purpose; this soulcrystal can be used in pve/pvp (exclude pvp if some demons prove to be OP) to release this demon to do your bidding. Basically a combination of enslave demon but then saved for another occasion.
That's the basic idea.
Some variations I thought up first/later;
- Soulcrystal could store demons and save them as your pet. This would come close to hunter way of taming pets. It would also contradict the lore of how warlocks don't care for their pets so much to keep them forever unlike hunters (sidenote: funny how our demons always are the same name-wise. DK pets are more realistic to the idea; using random generated names to make ghouls random)
- To avoid warlocks stocking up on all kinds of demons perhaps limit the amount of soulcrystals to 1 (making it unique). To make it different from hunters we make the soulcrystal consumed upon breaking it (using it). Then means you can save it but only used 1 time. If you want to use an enslaved demon again you need to create a soulcrystal and capture one again.
Downside is that it's not so practical when using in raids since it's harder to quit the raid just to go capture a new demon for your next encounter.
- Since enslaved demons isn't a new mechanic in the game there's not much tweaking (from my perspective) needed). The skills are the same as when you're on the spot where you enslave the demon. The only thing that's different is that you are "having" the enslaved demon later on (called when needed from the soulcrystal).
- Perhaps make the enslave demons scale with the player's level. This allows players to go capture low level demons and still make them useful on higher level fights. This would likely require more tweaking like the doomguard scaling.
- Make the demon start out enslaved when used. Perhaps 10 min enslaved - 20 min cooldown.
If you have more suggestions/ideas surrounding this topic please share.