I’ve started running Curse of Strahd and have been having a ton of fun making wacky homebrew things for my party and tweaking the module. Unbeknownst to the players so far, I have made them all a secret Dark Power trying to use them to usurp Strahd and Vampyr, and they’re just waiting to offer their dark gift.
For example, I have a druid with some fire giant ancestry who loves Produce Flame and is their front line, so he’ll be offered a slightly weaker Rage with the Path of the Storm Herald desert feature to use once per long rest. The celestial warlock would get charges to boost his Eldritch Blast damage and some secondary healing in exchange for sapping his life.
Giving my players powerful upgrades alongside typical class advancement can make some encounters harder to balance around, but as long as we’re all having fun who cares about balance??
Both as a player and a DM is theorising and imagining ways that different scenarios would go. Both tactical combat and social encounters. Even if the ideal circunstances don’t come up and my characters is not that broken or my players predicable enough for this to happen, It feels so good to make a decent build that makes sense or cool encounters.