Many of my commons would be red-flagged under nwo. While I'm still salty about some of the red flags, this is one of the cards I'd be fine redoing the ability to fit with nwo. I find the 4 lines flag to be silly, so I'm mainly concerned with the affecting another permanent and card advantage here.

"Affecting other permanents" is a bit too vaguely expressed, but it generally means making combat math harder to process since the combination of things to do (during combat) increases. Sorcery speed bounce doesn't do that. This is also why Benalish Trapper doesn't really break that rule since it pretty much makes the actual combat easier to process, not harder. Yeva's Forcemage isn't red flagged either as far as I know.

Even drawing the card is limited here and you pay it in tempo. If the draw there isn't guaranteed (you can't always get enough dudes with -1/-1 counters in limited) then it wouldn't be red flagged for that either. For example, a card like Blazing Volley isn't red flagged even though it could theoretically give you lots of card advantage, but it's not so likely to do so.

The main culprit here definitely is the text length you would rather ignore, but IMO here it would really server it's purpose. That text describes a quite convoluted process that has a trigger (etb), target (creature), effect (bounce), restriction (you control), and a condition (if had counter) that grants an additional bonus effect (draw card). Each of them is simple on its own, but when you pile them all up it becomes just slightly that more taxing all in all. Easiest way to explain the potential issue is that the card's text just keeps on going too long.

However, it's worth noty that the phrase "enters the battlefield" is given some leeway when it comes to text lengths - similarly to how the commonly used pseudokeyword trigger phrases of landfall and rally are as well.

That text length issue could be quite easily fixed here. The following fits three lines:

> When ~ cast, return target creature to its owner hand. If it had a counter on it, draw a card.

So obviously we should accept using ETB instead of cast since it's one of the most common phrases that appear in MTG as it is. So I would recommend

> When ~ ETBs, return target creature to its owner hand. If it had a counter on it, draw a card.

I'm pretty sure that using "that creature" isn't entirely necessary since it already uses the tense word "had" for it. Using generic counter as a conditional filler makes the card just more flexible.

EDIT1:

One problem here is that the effect is mandatory for some reason and may not be intuitive in that fashion. Obviously adding "you may" would help, but I think that would certainly be the final push to make it over the text limit since we've made several concessions already...

EDIT2: I seemingly just dropped the "you control" restriction from my suggestions without noticing it until now. I think that's a clue as well that this is just too wordy.

Yeah, the mandatory part is iffy. It's basically a drawback that is not cost as one because it can be used as card advantage.

I also would change it from "target" to "another target" (or use the cast trigger condition suggested above).

I don't know what the actual intent here is, but as a (mandatory) drawback this also seems harder to cost correctly.

The effect could not be mandatory, yeah. There's also no point in restricting the type of counter- that was the whole reason I worded blemish as I did. This card needs to be a hybrid though, and I don't think green gets to bounce opponents' creatures. Further, I think that bouncing an opponent's creature with the potential to draw would be pretty strong.