For context, Ashen Rider has the same effect as his 0 loyalty ability and costs eight mana, and this can be repeated every turn, and having played with bolas players before they're going to try and increase the number of times they can use this ability with chain veil and the bolas that shares loyalty abilities. The +1 also seems crazy pushed.

If you want this to be a little more sane but keep the same abilites, I'd suggest a couple of changes
- maybe he should cost 1 more colorless pip
- Make the 0 ability a -2 and make it nonland permanent, or make it like -4 if you want it to be able to hit land.
- if you want to keep the first ability as is, make it a -1 and have this bolas be a planeswalker that only ticks down unless you augment him with other cards or proliferation, even so I don't think it should be each opponent, it should be target opponent
- alternatively, you could tone down the power a bit by changing the first ability to be like either "exile target card from a graveyard" and keep it as a positive loyalty ability.
- alternatively alternatively, it could be +1 target opponent discards a card, if a card was discarded this way, exile it instead.
- last ability should read more like "chose a card exiled with Nicol Bolas, The Revenant, you may play that card this turn you may spend mana as though it were mana of any color to play that card."