well i can give you some info under my own experience:
pretty much, watch his behaviores first, all tagers will start off the same (well almost all of them) and be defensive. ignore this, we already know this. watch what he/she does later in the match, how is this tager trying to get close? what does he do under our lolhaku pressure?
how does this tager act in the air? does he super jump and mash JC to get closer? if its consistent then CH 2C, or FC hotaru him.
if hes jumpig JC then barriering try jump and air grab.
if hes just jumping (once) no super jump and barriering theres nothing you can do to stop the momentum unless you somehow, jump the exact moment he does and hit him, grab etc.
do not stay to close, poke from max range, even with 2A yes. an IBing tager is a deadly tager. 4c and JC are good but it doesnt stop his momentum.
learn what he does on the ground. if hes throwing out 5D>sledge you can easily 6D any of the sledges. if he 2Ds? use your 5D at long range, or 2D at short range.
his pressure: good ons usually trap you into getting (non-purple) 360s. IB his pressure and either poke him out, TK hotaru, or D his obvious next move, reacting is better though.
say you were grabbed into GF usually 1 of 4 things will occur.
1 they will attempt a 360 (yomi part 1)
2 they will attempt AC predicting you will jump. (yomi part 2)
3 sit and block waiting for an obvious reaction.
4 backdash into block or something else.
you have the risks of using hotaru, it beats 360s but ACs invincibilty beats hotaru so it will whiff, putting you both in neut.
if they block then its another mind game moment, they know we can jump off hotaru, but...will we jump or land? AC answers the jump but 360 answers the land.
petty much its a quick choice. guaging you opponent is the best thing you can do vs tager. also if you are consistent with it 4C,5C spark volt. they cant do anything for the first 3 seconds out of the 5 or 6 that magnetism lasts.
if you are maged then they usually become aggressive. using jD, 2D, 5D, and 4D to draw you closer. walking 360 A to pull you. normals and traps to 360 you. if they are in the air watch their second movement. it will come down to either jump and grab or 2C,hotaru them the reasons are stated earlier. stay on the ground. let him come to you. the more you work tager the better it is for you.
i gotta cut this short but heres another tip: dont out yourself in a corner, especially when you are maged. backing up to avoid him may have serious drawbacks.