Just checking Wiki page, and saw, that most minigames lack interests and fun around here.
How about adding Shades Of Mort'on? Would also make players to attend to do quest Rest In Pieces. Shadow sword required to kill them.
Shades could be added as Slayer task to both Chaeldar and Vannaka or other Slayer Masters. 40 - 100 kill count.

About minigame itself:
http://runescape.salmoneus.net/activities/shades-of-mortton.html

And keys, could give different imbue scrolls for fremmenik rings in game like, Berserker, Warrior, Archer or Seers. Making the one of the best rings in game, stat wise, and untradeable with fee of 50 perfect gold bars, per charging, seeing as people would just love to buy it.

Adding a new minigame would only make that new minigame active for a few weeks to a month. This doesn't solve the problem we are having with hosting minigames now. It's easy to hop in a game during dxp because everyone is there doing it since it is double tickets/tokens, but when it isn't dxp you have to scavenger players for 30 minutes trying to get a game started.

However, I think adding more minigames would be a nice addition. I think the minigame you've suggested would be nice, but personally I think Soul Wars would be a pretty intense minigame to have on an RSPS.

Adding a new minigame would only make that new minigame active for a few weeks to a month. This doesn't solve the problem we are having with hosting minigames now. It's easy to hop in a game during dxp because everyone is there doing it since it is double tickets/tokens, but when it isn't dxp you have to scavenger players for 30 minutes trying to get a game started.

However, I think adding more minigames would be a nice addition. I think the minigame you've suggested would be nice, but personally I think Soul Wars would be a pretty intense minigame to have on an RSPS.

Even with intense minigame like Soul Wars, you need respective rewards, and as much as I remember, only gamble or Slayer Monster Heads are different rewards, from what Pest Control offer nowadays in Emps-World. Still, Thanks for opinion. I respect you, for longer opinion then 2 sentences BS, which players tend to comment just to agree or disagree.