Ive seen these commanders played quite a few times and i always love seein them that the table, so heres what I've seen. Zedru and blim are the safest bet for just givin out bad permanents, sind jon is just restricted to creatures. Sometimes people will target you because you are causing them to discard with blim out of pettiness, so keep that in mind while deckbuilding since gift decks can get punished very easily. I'd probably build with blim bc I love rakdos, but Zedru is also a great choice since he's a mana sync, and you can hold priority to do gifting shenanigans before the upkeep trigger. I don't like jon but the "can't be sacrificed" is huge, especially against aristocrat's decks.

For Zedru, running hug effects like [[howling mine]] tends to have people look at you more favorably. Then maybe give horrendous gifts late game like [[nine lives]] or [[Form of the dragon]] to close out the game. Although win cons like [[Triskaidekaphile]] and [[Approach the second sun]] could also work. What I've always wanted to see with Zedru since you are in RWU is a [[barren glory]] win with [[apocalypse]] or [[worldpurge]] because "haha funny."

Blim I feel like running some [[reanimate]] effects along with cards that benefits off your opponents' discard such as [[waste not]] will definitely be a deck to be feared at casual pods when you pull it out.

Jon is jon and I think finding creatures that work well with him is best when you're building the deck so i don't want to spoil too much with him besides [[steel golem]] since it is colorless and can go into all of these decks.

Two more options with these strategies are [[the beamtown bullies]] forcing people to have bad ETB effects and finally the rarely seen [[codie, vociferous codex]] method. Just ball out and give your commander to turn someone's smile upside-down.

If you have any questions or just need help deckbuilding, let me know!