Let's just keep it out, what if your wanting to win, full game "16 players" and your are traitor with 2 others and they both jihad and together kill a total of 6 people. So now your stuck with killing 7 people alone.... It may not be overpowering and then again it maybe overpowering, but if it's used wrong it can seal the victory to innocent. I highly doubt you will get 8 people with the jihad maybe not even 6. It will just make games end faster if the traitors are kids and just what to homicide every-time their traitor =/
Edit:
If you do allow the jihad bomb in the game you it should cost:
- 3+ kills from yourself only
- 1 Credit
or
- Costs 3 credits at start
- Cost decreases for each kill until cost is 1.
of course both of those above are related but the second option lets you just pick up credits from other kills and let you purchase.