This team is something that can work very well or flop. It relies heavily on Twitch and Rammus executing there roles. This is not to say that the others role is not important it the two of them just need to do their jobs perfectly. This team has a good amout of cc,disables and zoning power which can prove very useful in team fights.
General Character Play
Twitch is my personal favorite character. In this team build he is played as the "Glass Cannon" of the team. He is the type of character that needs to do well or he will flop and be useless. The player needs to be ballsy with his actions and needs to gank often. He/she NEEDS to gank. This is the most important thing to this character is his ganking phase. He should take middle lane rush 6 and start his ganking phase. In team fights he should be one of the last ones to initiate so they can absorb the stuns and allow twitch to blow the other team up. You need to line up spray and pray to do the maximum possible damage to the squishes of the other team.
Rammus is a very basic tank character that is very durable. He should be the one initiating the team fights like any tank should. His focus should not be on actual health but on medigation items that provide extra armor and magic resistance. Sunfire cape is his most important health item, it provides a good amount of health and the aoe damage is very nice for him. Make sure to taunt off either their carries or taunt of the people focusing on yours. His ult makes for great use against pushing towers early.
Anivia is your CC bird that can take a beating, For this team you do NOT want to play her as a hard carry. Instead focus on ap tank items. A banshees veil is a very good item for her because it can get rid of a stun or magical effect and provides some extra health. A rod of ages is also a very nice item for her to have. Abysal septer is another item that gives some ap and survive ability. She should take the top 1v2 or 1v1 solo. Blocking with her wall can make or break a team fight if she can isolate characters.
Trundle is another favorite of mine, He is a very good person for picking out and isolating single members of a team and providing their own personal hell for them. He should jungle to give you the extra solo and like twitch should try to gank as much as possible. Building him as a durable character is also very important. Tri force is his core item that allows him to wreck the person he solos out because of he is constantly pocking the sheen effect. Attack speed and on hit effects such as madreds to tear through the tanks that are harder for twitch to kill are also very useful. Like anivia placement of your pilar is very imporant
Support, Support, Support. This is your role. You should take the support summoners to help your team and should do everything in your power to save them in team fights and when they are running from enemy players. You have you stun which should almost always be used on the enemy teams carry to disable them.
Rammus should initiate the fights like stated above, Anivia should try and stay out from the middle of the fight as much as possible so she can deal as much damage without being targeted. She is built durable so when she is she can live for a while and put up a fight. Trundle should run in right behind rammus and pick out the other teams fighter or bulkier character and try and solo him out and kill him. Taric needs to keep an eye on everyone and throw out heals whenever they are up. Stunning is also very imporant and like the heal should be tossed out whenever possible. Twitch is your carry, although this sounds a little strange let him sit back for a few secconds to let the inital aoe damage and cc effects from the enemy team be tossed out. while this is being done he should be positioning himself for spray and pray. Once you are in positon let the gunshots/arrows fly and blow up their team. Anivia and Trundle need to use their path bloking abilites to isolate people as best as they can.
This can be a very potent team is played right. It does rely heavily on your personal skill level with the characters and team execution of stuff.NEVER EVER EVER buy breserkers greaves on anyone.