Well it really depends on what you want to do exactly and how much you need the benefit.
You can pull SoE missions with your alts then complete it with your alt and your main to boost your main’s faction standings. Or you can use one to pull and share it among all of your alts that you make omega.
If your main or other character has low (especially if in negative) faction standings then I suggest first look up The Plan by @DeMichael_Crimson to see if there is an alternative and cheaper method than subbing additional omegas:
If your aim is to gain faction standings but already have them fairly high still there might be better options just yet so best to check if that is the case.
If you want to boost up the faction standing on your main for access to agents, for lower tax on trade and industry and such or if you want to give faction standings to all your alts but of course divided amongst them then for the same reasons you can do just have to make sure you use the proper approach and still worth considering other methods or if the end result is worth subbing for. Only you can decide.
You can read the details of the SoE here: The Blood-Stained Stars - EVE University Wiki
According to this:
Rewards
Completing the missions gives money but no LP. The more lucrative reward is the faction standing boost you get from the final mission. +7% to the empire faction of your choice with no derived standing changes (+8.75% with Social V). This is especially useful to those who have ruined their standing to below -2.00.
It takes considerable amount of time to complete it and it can only be repeated 3 months after completing it, however I think you can biomass a character and make a new one and start the SoE again on that new character (the character will pull the mission) and complete it with your target character (assume your main) so if you only want to raise faction standings on one character you can sub one of your alpha accounts that has an open slot and make the most out of a one month sub on that second account by recycling your puller character.
This sounds kind of excessive but I’ve checked:
https://support.eveonline.com/hc/en-us/articles/204873262-Known-Declared-Exploits
And there seem no rule against it so I assume this should be fine. Though do this at your own risk. If want to make sure drop a support ticket and ask the GMs before you sub the second account to see if this is really allowed to avoid getting into trouble later on.