It would be in the best interest of the person playing to only use the Trances and Egis of Primals that more than the WoL themselves, have access to. Â Phoenix is basically off limits, it's aether lost in the aether at the fall of Bahamut most likely. Shiva is another hard one, though I think that if you made your way to Akh Afah Amphitheater and did some attuning you may be able to find Shiva in there somewhere if you are already a SMN. Â Levi and Ramuh would be a bit easier, as a trance Ramuh would be reasonable, Levi an Egi or a trance, we only have information on why the former (Ramuh) has no Egi, whereas Levi has just never been done before.
The absorption of your Egi basically happens each time you revoke them. Â They are, as Souns stated, a split of your aether using the "taint" or absorbed aether of the particular primal you are summoning to give them form, which [the taint] falls over the area of their defeat, and lingers for some time after, usually believed to be in accordance with how strong said Primal was. Â This being considered, the use of their powers by absorbing them? Â I suppose you could, it would be better to maybe make your spells as a Thaumaturge cross-class a bit stronger maybe? Â The Trances seemed to be created to harness the residual aether which a very strong primal has left to be absorbed by the summoner, and so gives the summoner some iota of their abilities, so having the power of Ifrit, Garuda, and Titan within you may not actually give you the ability to use their powers beyond summoning an Egi, only because we know that they weren't nearly as strong as say Bahamut, and apparently not as strong as Ramuh, because we think of something Jana mentioned in terms of energy scales.
I hope some of the things shared here helped, the link Sounsyy both supplied and filled, is an invaluable collection information that we know up to now, and a good read of it could jog some ideas or help you set a guideline of how you want things to work for your character. Â Good luck!
The absorption of your Egi basically happens each time you revoke them. Â They are, as Souns stated, a split of your aether using the "taint" or absorbed aether of the particular primal you are summoning to give them form, which [the taint] falls over the area of their defeat, and lingers for some time after, usually believed to be in accordance with how strong said Primal was. Â This being considered, the use of their powers by absorbing them? Â I suppose you could, it would be better to maybe make your spells as a Thaumaturge cross-class a bit stronger maybe? Â The Trances seemed to be created to harness the residual aether which a very strong primal has left to be absorbed by the summoner, and so gives the summoner some iota of their abilities, so having the power of Ifrit, Garuda, and Titan within you may not actually give you the ability to use their powers beyond summoning an Egi, only because we know that they weren't nearly as strong as say Bahamut, and apparently not as strong as Ramuh, because we think of something Jana mentioned in terms of energy scales.
I hope some of the things shared here helped, the link Sounsyy both supplied and filled, is an invaluable collection information that we know up to now, and a good read of it could jog some ideas or help you set a guideline of how you want things to work for your character. Â Good luck!